diff --git a/.upgrade.yml b/.upgrade.yml
index 7ae535e..1f5fd04 100644
--- a/.upgrade.yml
+++ b/.upgrade.yml
@@ -55,3 +55,9 @@ mappings:
   EditableLiteralFieldTest: SilverStripe\UserForms\Tests\Model\EditableFormField\EditableLiteralFieldTest
   SecureEditableFileFieldTest: SilverStripe\UserForms\Tests\Model\EditableFormField\SecureEditableFileFieldTest
   UserDefinedForm_EmailRecipientConditionTest: SilverStripe\UserForms\Tests\Model\Recipient\EmailRecipientConditionTest
+
+warnings:
+  methods:
+    'SilverStripe\UserForms\Model\EditableFormField->EffectiveDisplayRules()':
+      message: 'EffectiveDisplayRules deprecated because of new support for conditional required field'
+      url: 'https://github.com/silverstripe/silverstripe-userforms/pull/770/'
diff --git a/client/dist/js/userforms.js b/client/dist/js/userforms.js
index 2fc19ca..e8c9a4b 100644
--- a/client/dist/js/userforms.js
+++ b/client/dist/js/userforms.js
@@ -1 +1 @@
-!function(t){function e(n){if(r[n])return r[n].exports;var i=r[n]={i:n,l:!1,exports:{}};return t[n].call(i.exports,i,i.exports,e),i.l=!0,i.exports}var r={};e.m=t,e.c=r,e.i=function(t){return t},e.d=function(t,r,n){e.o(t,r)||Object.defineProperty(t,r,{configurable:!1,enumerable:!0,get:n})},e.n=function(t){var r=t&&t.__esModule?function(){return t.default}:function(){return t};return e.d(r,"a",r),r},e.o=function(t,e){return Object.prototype.hasOwnProperty.call(t,e)},e.p="",e(e.s="./client/src/bundles/bundle.js")}({"./client/src/bundles/UserForms.js":function(t,e,r){"use strict";function n(t){return t&&t.__esModule?t:{default:t}}var i=r(1),s=n(i),o=r(0),a=n(o);(0,s.default)(document).ready(function(t){function e(e){return this.$el=e instanceof t?e:t(e),this.$el.find("h4").text(a.default._t("UserForms.ERROR_CONTAINER_HEADER","Please correct the following errors and try again:")),this}function r(r){var n=this;this.$el=r instanceof t?r:t(r);var i=this.$el.closest(".userform").data("inst");return this.$elButton=t(".step-button-wrapper[data-for='"+this.$el.prop("id")+"']"),this.viewed=!1,this.valid=!1,this.id=null,this.hide(),u.DISPLAY_ERROR_MESSAGES_AT_TOP&&(this.errorContainer=new e(this.$el.find(".error-container")),i.$el.on("userform.form.error",function(e,r){n.$el.is(":visible")&&t.each(r.errorList,function(e,r){n.errorContainer.updateErrorMessage(t(r.element),r.message)})}),i.$el.on("userform.form.valid",function(t,e){n.errorContainer.removeErrorMessage(e)})),this.$elButton.on("userform.field.hide userform.field.show",function(){i.$el.trigger("userform.form.conditionalstep")}),this}function n(e){var r=this;this.$el=e instanceof t?e:t(e),this.$buttons=this.$el.find(".step-button-jump"),this.$jsAlign=this.$el.find(".js-align");var n=this.$el.closest(".userform").data("inst");return this.$buttons.each(function(e,n){t(n).on("click",function(e){e.preventDefault();var n=parseInt(t(e.target).data("step"),10);r.$el.trigger("userform.progress.changestep",n)})}),n.$el.on("userform.form.changestep",function(t,e){r.update(e)}),n.$el.on("userform.form.conditionalstep",function(){var e=r.$buttons.filter(":visible");e.each(function(e,r){t(r).text(e+1)}),r.$el.find(".progress-bar").attr("aria-valuemax",e.length),r.$el.find(".total-step-number").text(e.length)}),this.$jsAlign.each(function(e,n){var i=t(n),s=100/(r.$jsAlign.length-1)*e,o=s+"%",a=i.innerWidth()/2*-1;i.css({left:o,marginLeft:a}),e===r.$jsAlign.length-1?i.css({marginLeft:2*a}):0===e&&i.css({marginLeft:0})}),this}function i(e){var r=this;return this.$el=e instanceof t?e:t(e),this.userformInstance=this.$el.closest(".userform").data("inst"),this.$prevButton=this.$el.find(".step-button-prev"),this.$nextButton=this.$el.find(".step-button-next"),this.$prevButton.parent().attr("aria-hidden",!1).show(),this.$nextButton.parent().attr("aria-hidden",!1).show(),this.$prevButton.on("click",function(t){t.preventDefault(),r.$el.trigger("userform.action.prev")}),this.$nextButton.on("click",function(t){t.preventDefault(),r.$el.trigger("userform.action.next")}),this.userformInstance.$el.on("userform.form.changestep userform.form.conditionalstep",function(){r.update()}),this}function s(r){var n=this;return this.$el=r instanceof t?r:t(r),this.steps=[],this.errorContainer=new e(this.$el.children(".error-container")),this.$el.on("userform.action.prev",function(){n.prevStep()}),this.$el.on("userform.action.next",function(){n.nextStep()}),this.$el.find(".userform-progress").on("userform.progress.changestep",function(t,e){n.jumpToStep(e-1)}),this.$el.on("userform.form.valid",function(t,e){n.errorContainer.removeStepLink(e)}),this.$el.validate(this.validationOptions),this.$el.find(".optionset.requiredField input").each(function(e,r){t(r).rules("add",{required:!0})}),this}function o(o,d){var f=this,c=t(d);if(0!==c.length){u.ENABLE_LIVE_VALIDATION=void 0!==c.data("livevalidation"),u.DISPLAY_ERROR_MESSAGES_AT_TOP=void 0!==c.data("toperrors"),!1===u.ENABLE_LIVE_VALIDATION&&t.extend(s.prototype.validationOptions,{onfocusout:!1}),u.DISPLAY_ERROR_MESSAGES_AT_TOP&&t.extend(s.prototype.validationOptions,{invalidHandler:function(t,e){c.trigger("userform.form.error",[e])},onfocusout:!1}),c.find(".userform-progress, .step-navigation").attr("aria-hidden",!1).show(),t.extend(r.prototype,l),t.extend(e.prototype,l);var h=new s(c);c.data("inst",h),u.HIDE_FIELD_LABELS&&c.find("label.left").each(function(){var e=t(f);t('[name="'+e.attr("for")+'"]').attr("placeholder",e.text()),e.remove()}),h.$el.find(".form-step").each(function(t,e){var n=new r(e);h.addStep(n)}),h.setCurrentStep(h.steps[0]);var p=c.find(".userform-progress");p.length&&new n(p).update(0);var m=c.find(".step-navigation");m.length&&new i(m).update(),t(document).on("click","input.text[data-showcalendar]",function(){var e=t(f);e.ssDatepicker(),e.data("datepicker")&&e.datepicker("show")}),setInterval(function(){t.ajax({url:"UserDefinedFormController/ping"})},18e4),void 0!==c.areYouSure&&c.areYouSure({message:a.default._t("UserForms.LEAVE_CONFIRMATION","You have unsaved changes!")})}}var u={},l={show:function(){this.$el.attr("aria-hidden",!1).show()},hide:function(){this.$el.attr("aria-hidden",!0).hide()}};e.prototype.hasErrors=function(){return this.$el.find(".error-list").children().length>0},e.prototype.removeErrorMessage=function(t){this.$el.find("#"+t+"-top-error").remove(),this.hasErrors()||this.hide()},e.prototype.addStepLink=function(e){var r=this.$el.closest(".userform").data("inst"),n=e.$el.attr("id")+"-error-link",i=this.$el.find("#"+n),s=e.$el.attr("id"),o=e.$el.data("title");i.length||(i=t('<li id="'+n+'"><a href="#'+s+'">'+o+"</a></li>"),i.on("click",function(t){t.preventDefault(),r.jumpToStep(e.id)}),this.$el.find(".error-list").append(i))},e.prototype.removeStepLink=function(e){var r=t("#"+e).closest(".form-step").attr("id");this.$el.find("#"+r+"-error-link").remove(),this.$el.find(".error-list").is(":empty")&&this.hide()},e.prototype.updateErrorMessage=function(e,r){var n=this,i=e.attr("id"),s="#"+i,o=i+"-top-error",a=t("#"+o),u=e.attr("aria-describedby");if(!r)return void a.addClass("fixed");a.removeClass("fixed"),this.show(),1===a.length?a.show().find("a").html(r):(e.closest(".field[id]").each(function(){s="#"+t(n).attr("id")}),a=t("<li><a></a></li>"),a.attr("id",o).find("a").attr("href",location.pathname+location.search+s).html(r),this.$el.find("ul").append(a),u?u.match(new RegExp("\\b"+o+"\\b"))||(u+=" "+o):u=o,e.attr("aria-describedby",u))},r.prototype.conditionallyHidden=function(){return!this.$elButton.find("button").is(":visible")},n.prototype.update=function(e){var r=t(this.$el.parent(".userform").find(".form-step")[e]),n=0,i=e/(this.$buttons.length-1)*100;this.$buttons.each(function(r,i){return!(r>e||(t(i).is(":visible")&&(n+=1),0))}),this.$el.find(".current-step-number").each(function(e,r){t(r).text(n)}),this.$el.find("[aria-valuenow]").each(function(e,r){t(r).attr("aria-valuenow",n)}),this.$buttons.each(function(e,r){var i=t(r),s=i.parent();if(parseInt(i.data("step"),10)===n&&i.is(":visible"))return s.addClass("current viewed"),void i.removeAttr("disabled");s.removeClass("current")}),this.$el.siblings(".progress-title").text(r.data("title")),i=i?i+"%":"",this.$el.find(".progress-bar").width(i)},i.prototype.update=function(){var t=this.userformInstance.steps.length,e=this.userformInstance.currentStep?this.userformInstance.currentStep.id:0,r=null,n=null;for(this.$el.find(".step-button-prev")[0===e?"hide":"show"](),r=t-1;r>=0;r--)if(n=this.userformInstance.steps[r],!n.conditionallyHidden()){this.$el.find(".step-button-next")[e>=r?"hide":"show"](),this.$el.find(".btn-toolbar")[e>=r?"show":"hide"]();break}},s.prototype.validationOptions={ignore:":hidden,ul",errorClass:"error",errorElement:"span",errorPlacement:function(t,e){t.addClass("message"),e.is(":radio")||e.parents(".checkboxset").length>0?t.appendTo(e.closest(".middleColumn")):e.parents(".checkbox").length>0?t.appendTo(e.closest(".field")):t.insertAfter(e)},invalidHandler:function(t,e){setTimeout(function(){e.currentElements.filter(".error").first().focus()},0)},submitHandler:function(e){var r=!0,n=t(e).closest(".userform").data("inst");n.currentStep&&(n.currentStep.valid=t(e).valid()),t.each(n.steps,function(t,e){e.valid||e.conditionallyHidden()||(r=!1,n.errorContainer.addStepLink(e))}),r?(t(e).removeClass("dirty"),e.submit(),n.$el.trigger("userform.form.submit")):n.errorContainer.show()},success:function(e){var r=t(e).closest(".userform").data("inst"),n=t(e).attr("id"),i=n.substr(0,n.indexOf("-error")).replace(/[\\[\\]]/,"");e.remove(),r.$el.trigger("userform.form.valid",[i])}},s.prototype.addStep=function(t){t instanceof r&&(t.id=this.steps.length,this.steps.push(t))},s.prototype.setCurrentStep=function(t){t instanceof r&&(this.currentStep=t,this.currentStep.show(),this.currentStep.viewed=!0,this.currentStep.$el.addClass("viewed"))},s.prototype.jumpToStep=function(t,e){var r=this.steps[t],n=!1,i=void 0===e||e;if(void 0!==r){if(r.conditionallyHidden())return void(i?this.jumpToStep(t+1):this.jumpToStep(t-1));n=this.$el.valid(),this.currentStep.valid=n,!1===n&&!1===r.viewed||(this.currentStep.hide(),this.setCurrentStep(r),this.$el.trigger("userform.form.changestep",[r.id]))}},s.prototype.nextStep=function(){this.jumpToStep(this.steps.indexOf(this.currentStep)+1,!0)},s.prototype.prevStep=function(){this.jumpToStep(this.steps.indexOf(this.currentStep)-1,!1)},t(".userform").each(o)})},"./client/src/bundles/bundle.js":function(t,e,r){"use strict";r("./client/src/bundles/UserForms.js")},0:function(t,e){t.exports=i18n},1:function(t,e){t.exports=jQuery}});
\ No newline at end of file
+!function(t){function e(n){if(r[n])return r[n].exports;var i=r[n]={i:n,l:!1,exports:{}};return t[n].call(i.exports,i,i.exports,e),i.l=!0,i.exports}var r={};e.m=t,e.c=r,e.i=function(t){return t},e.d=function(t,r,n){e.o(t,r)||Object.defineProperty(t,r,{configurable:!1,enumerable:!0,get:n})},e.n=function(t){var r=t&&t.__esModule?function(){return t.default}:function(){return t};return e.d(r,"a",r),r},e.o=function(t,e){return Object.prototype.hasOwnProperty.call(t,e)},e.p="",e(e.s="./client/src/bundles/bundle.js")}({"./client/src/bundles/UserForms.js":function(t,e,r){"use strict";function n(t){return t&&t.__esModule?t:{default:t}}var i=r(1),s=n(i),o=r(0),a=n(o);(0,s.default)(document).ready(function(t){function e(e){return this.$el=e instanceof t?e:t(e),this.$el.find("h4").text(a.default._t("UserForms.ERROR_CONTAINER_HEADER","Please correct the following errors and try again:")),this}function r(r){var n=this;this.$el=r instanceof t?r:t(r);var i=this.$el.closest(".userform").data("inst");return this.$elButton=t(".step-button-wrapper[data-for='"+this.$el.prop("id")+"']"),this.viewed=!1,this.valid=!1,this.id=null,this.hide(),u.DISPLAY_ERROR_MESSAGES_AT_TOP&&(this.errorContainer=new e(this.$el.find(".error-container")),i.$el.on("userform.form.error",function(e,r){n.$el.is(":visible")&&t.each(r.errorList,function(e,r){n.errorContainer.updateErrorMessage(t(r.element),r.message)})}),i.$el.on("userform.form.valid",function(t,e){n.errorContainer.removeErrorMessage(e)})),this.$elButton.on("userform.field.hide userform.field.show",function(){i.$el.trigger("userform.form.conditionalstep")}),this}function n(e){var r=this;this.$el=e instanceof t?e:t(e),this.$buttons=this.$el.find(".step-button-jump"),this.$jsAlign=this.$el.find(".js-align");var n=this.$el.closest(".userform").data("inst");return this.$buttons.each(function(e,n){t(n).on("click",function(e){e.preventDefault();var n=parseInt(t(e.target).data("step"),10);r.$el.trigger("userform.progress.changestep",n)})}),n.$el.on("userform.form.changestep",function(t,e){r.update(e)}),n.$el.on("userform.form.conditionalstep",function(){var e=r.$buttons.filter(":visible");e.each(function(e,r){t(r).text(e+1)}),r.$el.find(".progress-bar").attr("aria-valuemax",e.length),r.$el.find(".total-step-number").text(e.length)}),this.$jsAlign.each(function(e,n){var i=t(n),s=100/(r.$jsAlign.length-1)*e,o=s+"%",a=i.innerWidth()/2*-1;i.css({left:o,marginLeft:a}),e===r.$jsAlign.length-1?i.css({marginLeft:2*a}):0===e&&i.css({marginLeft:0})}),this}function i(e){var r=this;return this.$el=e instanceof t?e:t(e),this.userformInstance=this.$el.closest(".userform").data("inst"),this.$prevButton=this.$el.find(".step-button-prev"),this.$nextButton=this.$el.find(".step-button-next"),this.$prevButton.parent().attr("aria-hidden",!1).show(),this.$nextButton.parent().attr("aria-hidden",!1).show(),this.$prevButton.on("click",function(t){t.preventDefault(),r.$el.trigger("userform.action.prev")}),this.$nextButton.on("click",function(t){t.preventDefault(),r.$el.trigger("userform.action.next")}),this.userformInstance.$el.on("userform.form.changestep userform.form.conditionalstep",function(){r.update()}),this}function s(r){var n=this;return this.$el=r instanceof t?r:t(r),this.steps=[],this.errorContainer=new e(this.$el.children(".error-container")),this.$el.on("userform.action.prev",function(){n.prevStep()}),this.$el.on("userform.action.next",function(){n.nextStep()}),this.$el.find(".userform-progress").on("userform.progress.changestep",function(t,e){n.jumpToStep(e-1)}),this.$el.on("userform.form.valid",function(t,e){n.errorContainer.removeStepLink(e)}),this.$el.validate(this.validationOptions),this.$el.find(".optionset.requiredField input").each(function(e,r){t(r).rules("add",{required:!0})}),this}function o(o,d){var f=this,c=t(d);if(0!==c.length){u.ENABLE_LIVE_VALIDATION=void 0!==c.data("livevalidation"),u.DISPLAY_ERROR_MESSAGES_AT_TOP=void 0!==c.data("toperrors"),!1===u.ENABLE_LIVE_VALIDATION&&t.extend(s.prototype.validationOptions,{onfocusout:!1}),u.DISPLAY_ERROR_MESSAGES_AT_TOP&&t.extend(s.prototype.validationOptions,{invalidHandler:function(t,e){c.trigger("userform.form.error",[e])},onfocusout:!1}),c.find(".userform-progress, .step-navigation").attr("aria-hidden",!1).show(),t.extend(r.prototype,l),t.extend(e.prototype,l);var h=new s(c);c.data("inst",h),u.HIDE_FIELD_LABELS&&c.find("label.left").each(function(){var e=t(f);t('[name="'+e.attr("for")+'"]').attr("placeholder",e.text()),e.remove()}),h.$el.find(".form-step").each(function(t,e){var n=new r(e);h.addStep(n)}),h.setCurrentStep(h.steps[0]);var p=c.find(".userform-progress");p.length&&new n(p).update(0);var m=c.find(".step-navigation");m.length&&new i(m).update(),t(document).on("click","input.text[data-showcalendar]",function(){var e=t(f);e.ssDatepicker(),e.data("datepicker")&&e.datepicker("show")}),setInterval(function(){t.ajax({url:"UserDefinedFormController/ping"})},18e4),void 0!==c.areYouSure&&c.areYouSure({message:a.default._t("UserForms.LEAVE_CONFIRMATION","You have unsaved changes!")})}}var u={},l={show:function(){this.$el.attr("aria-hidden",!1).show()},hide:function(){this.$el.attr("aria-hidden",!0).hide()}};e.prototype.hasErrors=function(){return this.$el.find(".error-list").children().length>0},e.prototype.removeErrorMessage=function(t){this.$el.find("#"+t+"-top-error").remove(),this.hasErrors()||this.hide()},e.prototype.addStepLink=function(e){var r=this.$el.closest(".userform").data("inst"),n=e.$el.attr("id")+"-error-link",i=this.$el.find("#"+n),s=e.$el.attr("id"),o=e.$el.data("title");i.length||(i=t('<li id="'+n+'"><a href="#'+s+'">'+o+"</a></li>"),i.on("click",function(t){t.preventDefault(),r.jumpToStep(e.id)}),this.$el.find(".error-list").append(i))},e.prototype.removeStepLink=function(e){var r=t("#"+e).closest(".form-step").attr("id");this.$el.find("#"+r+"-error-link").remove(),this.$el.find(".error-list").is(":empty")&&this.hide()},e.prototype.updateErrorMessage=function(e,r){var n=this,i=e.attr("id"),s="#"+i,o=i+"-top-error",a=t("#"+o),u=e.attr("aria-describedby");if(!r)return void a.addClass("fixed");a.removeClass("fixed"),this.show(),1===a.length?a.show().find("a").html(r):(e.closest(".field[id]").each(function(){s="#"+t(n).attr("id")}),a=t("<li><a></a></li>"),a.attr("id",o).find("a").attr("href",location.pathname+location.search+s).html(r),this.$el.find("ul").append(a),u?u.match(new RegExp("\\b"+o+"\\b"))||(u+=" "+o):u=o,e.attr("aria-describedby",u))},r.prototype.conditionallyHidden=function(){return!this.$elButton.find("button").is(":visible")},n.prototype.update=function(e){var r=t(this.$el.parent(".userform").find(".form-step")[e]),n=0,i=e/(this.$buttons.length-1)*100;this.$buttons.each(function(r,i){return!(r>e||(t(i).is(":visible")&&(n+=1),0))}),this.$el.find(".current-step-number").each(function(e,r){t(r).text(n)}),this.$el.find("[aria-valuenow]").each(function(e,r){t(r).attr("aria-valuenow",n)}),this.$buttons.each(function(e,r){var i=t(r),s=i.parent();if(parseInt(i.data("step"),10)===n&&i.is(":visible"))return s.addClass("current viewed"),void i.removeAttr("disabled");s.removeClass("current")}),this.$el.siblings(".progress-title").text(r.data("title")),i=i?i+"%":"",this.$el.find(".progress-bar").width(i)},i.prototype.update=function(){var t=this.userformInstance.steps.length,e=this.userformInstance.currentStep?this.userformInstance.currentStep.id:0,r=null,n=null;for(this.$el.find(".step-button-prev")[0===e?"hide":"show"](),r=t-1;r>=0;r--)if(n=this.userformInstance.steps[r],!n.conditionallyHidden()){this.$el.find(".step-button-next")[e>=r?"hide":"show"](),this.$el.find(".btn-toolbar")[e>=r?"show":"hide"]();break}},s.prototype.validationOptions={ignore:":hidden,ul",errorClass:"error",errorElement:"span",errorPlacement:function(t,e){t.addClass("message"),e.is(":radio")||e.parents(".checkboxset").length>0?t.appendTo(e.closest(".middleColumn")):e.parents(".checkbox").length>0?t.appendTo(e.closest(".field")):t.insertAfter(e)},invalidHandler:function(t,e){setTimeout(function(){e.currentElements.filter(".error").first().focus()},0)},submitHandler:function(e){var r=!0,n=t(e).closest(".userform").data("inst");n.currentStep&&(n.currentStep.valid=t(e).valid()),t.each(n.steps,function(t,e){e.valid||e.conditionallyHidden()||(r=!1,n.errorContainer.addStepLink(e))}),r?(t(e).find(".field.requiredField.hide input").removeAttr("required aria-required data-rule-required").valid(),t(e).removeClass("dirty"),e.submit(),n.$el.trigger("userform.form.submit")):n.errorContainer.show()},success:function(e){var r=t(e).closest(".userform").data("inst"),n=t(e).attr("id"),i=n.substr(0,n.indexOf("-error")).replace(/[\\[\\]]/,"");e.remove(),r.$el.trigger("userform.form.valid",[i])}},s.prototype.addStep=function(t){t instanceof r&&(t.id=this.steps.length,this.steps.push(t))},s.prototype.setCurrentStep=function(t){t instanceof r&&(this.currentStep=t,this.currentStep.show(),this.currentStep.viewed=!0,this.currentStep.$el.addClass("viewed"))},s.prototype.jumpToStep=function(t,e){var r=this.steps[t],n=!1,i=void 0===e||e;if(void 0!==r){if(r.conditionallyHidden())return void(i?this.jumpToStep(t+1):this.jumpToStep(t-1));n=this.$el.valid(),this.currentStep.valid=n,!1===n&&!1===r.viewed||(this.currentStep.hide(),this.setCurrentStep(r),this.$el.trigger("userform.form.changestep",[r.id]))}},s.prototype.nextStep=function(){this.jumpToStep(this.steps.indexOf(this.currentStep)+1,!0)},s.prototype.prevStep=function(){this.jumpToStep(this.steps.indexOf(this.currentStep)-1,!1)},t(".userform").each(o)})},"./client/src/bundles/bundle.js":function(t,e,r){"use strict";r("./client/src/bundles/UserForms.js")},0:function(t,e){t.exports=i18n},1:function(t,e){t.exports=jQuery}});
\ No newline at end of file
diff --git a/client/src/bundles/UserForms.js b/client/src/bundles/UserForms.js
index a740cdf..6289e9b 100644
--- a/client/src/bundles/UserForms.js
+++ b/client/src/bundles/UserForms.js
@@ -523,6 +523,10 @@ jQuery(document).ready(($) => {
       });
 
       if (isValid) {
+        // Remove required attributes on hidden fields
+        $(form).find('.field.requiredField.hide input')
+          .removeAttr('required aria-required data-rule-required').valid();
+
         // When using the "are you sure?" plugin, ensure the form immediately submits.
         $(form).removeClass('dirty');
 
diff --git a/code/Extension/UserFormValidator.php b/code/Extension/UserFormValidator.php
index d0306bb..461734d 100644
--- a/code/Extension/UserFormValidator.php
+++ b/code/Extension/UserFormValidator.php
@@ -31,7 +31,7 @@ class UserFormValidator extends RequiredFields
                 // Page at top level, or after another page is ok
                 if (empty($stack) || (count($stack) === 1 && $stack[0] instanceof EditableFormStep)) {
                     $stack = array($field);
-                    $conditionalStep = $field->EffectiveDisplayRules()->count() > 0;
+                    $conditionalStep = $field->DisplayRules()->count() > 0;
                     continue;
                 }
 
diff --git a/code/Form/UserForm.php b/code/Form/UserForm.php
index 6211dda..d6a2c1b 100644
--- a/code/Form/UserForm.php
+++ b/code/Form/UserForm.php
@@ -8,7 +8,6 @@ use SilverStripe\Control\Session;
 use SilverStripe\Forms\FieldList;
 use SilverStripe\Forms\Form;
 use SilverStripe\Forms\FormAction;
-use SilverStripe\Forms\RequiredFields;
 use SilverStripe\UserForms\FormField\UserFormsStepField;
 use SilverStripe\UserForms\FormField\UserFormsFieldList;
 
@@ -175,7 +174,7 @@ class UserForm extends Form
             ->filter('Required', true)
             ->column('Name');
         $requiredNames = array_merge($requiredNames, $this->getEmailRecipientRequiredFields());
-        $required = new RequiredFields($requiredNames);
+        $required = new UserFormsRequiredFields($requiredNames);
         $this->extend('updateRequiredFields', $required);
         $required->setForm($this);
         return $required;
diff --git a/code/Form/UserFormsRequiredFields.php b/code/Form/UserFormsRequiredFields.php
new file mode 100644
index 0000000..70b13ff
--- /dev/null
+++ b/code/Form/UserFormsRequiredFields.php
@@ -0,0 +1,150 @@
+<?php
+
+namespace SilverStripe\UserForms\Form;
+
+use InvalidArgumentException;
+use SilverStripe\Dev\Debug;
+use SilverStripe\Forms\FileField;
+use SilverStripe\Forms\FormField;
+use SilverStripe\Forms\RequiredFields;
+use SilverStripe\ORM\ArrayLib;
+use SilverStripe\UserForms\Model\EditableFormField;
+
+/**
+ * An extension of RequiredFields which handles conditionally required fields.
+ *
+ * A conditionally required is a field that is required, but can be hidden by display rules.
+ * When it is visible, (according to the submitted form data) it will be validated as required.
+ * When it is hidden, it will skip required validation.
+ *
+ * Required fields will be validated as usual.
+ * Conditionally required fields will be validated IF the display rules are satisfied in the submitted dataset.
+ */
+class UserFormsRequiredFields extends RequiredFields
+{
+    /**
+     * Allows validation of fields via specification of a php function for
+     * validation which is executed after the form is submitted.
+     *
+     * @param array $data
+     *
+     * @return bool
+     */
+    public function php($data)
+    {
+        $valid = true;
+        $fields = $this->form->Fields();
+
+        foreach ($fields as $field) {
+            $valid = ($field->validate($this) && $valid);
+        }
+
+        if (empty($this->required)) {
+            return $valid;
+        }
+
+        foreach ($this->required as $fieldName) {
+            if (!$fieldName) {
+                continue;
+            }
+
+            // get form field
+            if ($fieldName instanceof FormField) {
+                $formField = $fieldName;
+                $fieldName = $fieldName->getName();
+            } else {
+                $formField = $fields->dataFieldByName($fieldName);
+            }
+
+            // get editable form field - owns display rules for field
+            $editableFormField = $this->getEditableFormFieldByName($fieldName);
+
+            // Validate if the field is displayed
+            $error =
+                $editableFormField->isDisplayed($data) &&
+                $this->validateRequired($formField, $data);
+
+            // handle error case
+            if ($formField && $error) {
+                $this->handleError($formField, $fieldName);
+                $valid = false;
+            }
+        }
+
+        return $valid;
+    }
+
+    /**
+     * Retrieve an Editable Form field by its name.
+     * @param string $name
+     * @return EditableFormField
+     */
+    private function getEditableFormFieldByName($name)
+    {
+        $field = EditableFormField::get()->filter(['Name' => $name])->first();
+
+        if ($field) {
+            return $field;
+        }
+
+        // This should happen if form field data got corrupted
+        throw new InvalidArgumentException(sprintf(
+            'Could not find EditableFormField with name `%s`',
+            $name
+        ));
+    }
+
+    /**
+     * Check if the validation rules for the specified field are met by the provided data.
+     *
+     * @note Logic replicated from php() method of parent class `SilverStripe\Forms\RequiredFields`
+     * @param EditableFormField $field
+     * @param array $data
+     * @return bool
+     */
+    private function validateRequired(FormField $field, array $data)
+    {
+        $error = false;
+        $fieldName = $field->getName();
+        // submitted data for file upload fields come back as an array
+        $value = isset($data[$fieldName]) ? $data[$fieldName] : null;
+
+        if (is_array($value)) {
+            if ($field instanceof FileField && isset($value['error']) && $value['error']) {
+                $error = true;
+            } else {
+                $error = (count($value)) ? false : true;
+            }
+        } else {
+            // assume a string or integer
+            $error = (strlen($value)) ? false : true;
+        }
+
+        return $error;
+    }
+
+    /**
+     * Register an error for the provided field.
+     * @param FormField $formField
+     * @param string $fieldName
+     * @return void
+     */
+    private function handleError(FormField $formField, $fieldName)
+    {
+        $errorMessage = _t(
+            'SilverStripe\\Forms\\Form.FIELDISREQUIRED',
+            '{name} is required',
+            [
+                'name' => strip_tags(
+                    '"' . ($formField->Title() ? $formField->Title() : $fieldName) . '"'
+                )
+            ]
+        );
+
+        if ($msg = $formField->getCustomValidationMessage()) {
+            $errorMessage = $msg;
+        }
+
+        $this->validationError($fieldName, $errorMessage, "required");
+    }
+}
diff --git a/code/Model/EditableCustomRule.php b/code/Model/EditableCustomRule.php
index e3951bf..c2fd544 100644
--- a/code/Model/EditableCustomRule.php
+++ b/code/Model/EditableCustomRule.php
@@ -2,6 +2,7 @@
 
 namespace SilverStripe\UserForms\Model;
 
+use InvalidArgumentException;
 use LogicException;
 use SilverStripe\CMS\Controllers\CMSMain;
 use SilverStripe\Control\Controller;
@@ -88,7 +89,7 @@ class EditableCustomRule extends DataObject
      * Return whether a user can create an object of this type
      *
      * @param Member $member
-     * @param array $context Virtual parameter to allow context to be passed in to check
+     * @param array  $context Virtual parameter to allow context to be passed in to check
      * @return bool
      */
     public function canCreate($member = null, $context = [])
@@ -230,6 +231,63 @@ class EditableCustomRule extends DataObject
         return $result;
     }
 
+
+    /**
+     * Determines whether the rule is satisfied, based on provided form data.
+     * Used for php validation of required conditional fields
+     *
+     * @param array $data Submitted form data
+     * @return boolean
+     * @throws LogicException Invalid ConditionOption is set for this rule.
+     */
+    public function validateAgainstFormData(array $data)
+    {
+
+        $controllingField = $this->ConditionField();
+
+        if (!isset($data[$controllingField->Name])) {
+            return false;
+        }
+
+        $valid = false;
+
+        $targetFieldValue = $this->FieldValue;
+        $actualFieldValue = $data[$controllingField->Name];
+
+        switch ($this->ConditionOption) {
+            case 'IsNotBlank':
+                $valid = ($actualFieldValue !== '');
+                break;
+            case 'IsBlank':
+                $valid = ($actualFieldValue === '');
+                break;
+            case 'HasValue':
+                $valid = ($actualFieldValue === $targetFieldValue);
+                break;
+            case 'ValueNot':
+                $valid = ($actualFieldValue !== $targetFieldValue);
+                break;
+            case 'ValueLessThan':
+                $valid = ($actualFieldValue < $targetFieldValue);
+                break;
+            case 'ValueLessThanEqual':
+                $valid = ($actualFieldValue <= $targetFieldValue);
+                break;
+            case 'ValueGreaterThan':
+                $valid = ($actualFieldValue > $targetFieldValue);
+                break;
+            case 'ValueGreaterThanEqual':
+                $valid = ($actualFieldValue >= $targetFieldValue);
+                break;
+            default:
+                throw new LogicException("Unhandled rule {$this->ConditionOption}");
+                break;
+        }
+
+        return $valid;
+    }
+
+
     /**
      * Returns the opposite visibility function for the value of the initial visibility field, e.g. show/hide. This
      * will toggle the "hide" class either way, which is handled by CSS.
diff --git a/code/Model/EditableFormField.php b/code/Model/EditableFormField.php
index 41000a6..b85c67d 100755
--- a/code/Model/EditableFormField.php
+++ b/code/Model/EditableFormField.php
@@ -57,7 +57,7 @@ use Symbiote\GridFieldExtensions\GridFieldEditableColumns;
  * @property boolean $ShowOnLoad
  * @property string $DisplayRulesConjunction
  * @method UserDefinedForm Parent() Parent page
- * @method DataList DisplayRules() List of EditableCustomRule objects
+ * @method DataList|EditableCustomRule[] DisplayRules() List of EditableCustomRule objects
  * @mixin Versioned
  */
 class EditableFormField extends DataObject
@@ -352,19 +352,6 @@ class EditableFormField extends DataObject
      */
     protected function getDisplayRuleFields()
     {
-        // Check display rules
-        if ($this->Required) {
-            return FieldList::create(
-                LiteralField::create(
-                    'DisplayRulesNotEnabled',
-                    '<div class="alert alert-warning">' . _t(
-                        __CLASS__.'.DISPLAY_RULES_DISABLED',
-                        'Display rules are not enabled for required fields. Please uncheck "Is this field Required?" under "Validation" to re-enable.'
-                    ) . '</div>'
-                )
-            );
-        }
-
         $allowedClasses = array_keys($this->getEditableFieldClasses(false));
         $editableColumns = new GridFieldEditableColumns();
         $editableColumns->setDisplayFields([
@@ -943,6 +930,7 @@ class EditableFormField extends DataObject
      * Determine effective display rules for this field.
      *
      * @return SS_List
+     * @deprecated 5.6 No longer needed because of support for conditional required field.
      */
     public function EffectiveDisplayRules()
     {
@@ -972,7 +960,7 @@ class EditableFormField extends DataObject
 
         // Check for field dependencies / default
         /** @var EditableCustomRule $rule */
-        foreach ($this->EffectiveDisplayRules() as $rule) {
+        foreach ($this->DisplayRules() as $rule) {
             // Get the field which is effected
             /** @var EditableFormField $formFieldWatch */
             $formFieldWatch = DataObject::get_by_id(EditableFormField::class, $rule->ConditionFieldID);
@@ -1003,6 +991,48 @@ class EditableFormField extends DataObject
         return (count($result['selectors'])) ? $result : null;
     }
 
+    /**
+     * Check if this EditableFormField is displayed based on its DisplayRules and the provided data.
+     * @param array $data
+     * @return bool
+     */
+    public function isDisplayed(array $data)
+    {
+        $displayRules = $this->DisplayRules();
+
+        if ($displayRules->count() === 0) {
+            // If no display rule have been defined, isDisplayed equals the ShowOnLoad property
+            return $this->ShowOnLoad;
+        }
+
+        $conjunction = $this->DisplayRulesConjunctionNice();
+
+        // && start with true and find and condition that doesn't satisfy
+        // || start with false and find and condition that satisfies
+        $conditionsSatisfied = ($conjunction === '&&');
+
+        foreach ($displayRules as $rule) {
+            $controllingField = $rule->ConditionField();
+
+            // recursively check - if any of the dependant fields are hidden, assume the rule can not be satisfied
+            $ruleSatisfied = $controllingField->isDisplayed($data) && $rule->validateAgainstFormData($data);
+
+            if ($conjunction === '||' && $ruleSatisfied) {
+                $conditionsSatisfied = true;
+                break;
+            }
+            if ($conjunction === '&&' && !$ruleSatisfied) {
+                $conditionsSatisfied = false;
+                break;
+            }
+        }
+
+        // initially displayed - condition fails || initially hidden, condition passes
+        $startDisplayed = $this->ShowOnLoad;
+        return ($startDisplayed xor $conditionsSatisfied);
+    }
+
+
     /**
      * Replaces the set DisplayRulesConjunction with their JS logical operators
      * @return string
diff --git a/code/Model/EditableFormField/Validator.php b/code/Model/EditableFormField/Validator.php
index 2836a21..29c9242 100644
--- a/code/Model/EditableFormField/Validator.php
+++ b/code/Model/EditableFormField/Validator.php
@@ -39,43 +39,6 @@ class Validator extends RequiredFields
             return false;
         }
 
-        // When the record is unsaved and the classname is not set throw an error
-        if ((!$this->record || !$this->record->exists()) && (!isset($data['ClassName']) || empty($data['ClassName']))) {
-            $this->validationError(
-                'ClassName',
-                _t(
-                    __CLASS__ . 'CLASSNAME_ERROR',
-                    'You need to select a field type before you can create the field'
-                )
-            );
-            return false;
-        }
-
-        // Skip unsaved records
-        if (!$this->record || !$this->record->exists()) {
-            return true;
-        }
-
-        // Skip validation if not required
-        if (empty($data['Required'])) {
-            return;
-        }
-
-        // Skip validation if no rules
-        $count = EditableCustomRule::get()->filter('ParentID', $this->record->ID)->count();
-        if ($count == 0) {
-            return true;
-        }
-
-        // Both required = true and rules > 0 should error
-        $this->validationError(
-            'Required_Error',
-            _t(
-                __CLASS__.'.REQUIRED_ERROR',
-                'Form fields cannot be required and have conditional display rules.'
-            ),
-            'error'
-        );
-        return false;
+        return true;
     }
 }
diff --git a/lang/en.yml b/lang/en.yml
index ba8e338..5e424ed 100644
--- a/lang/en.yml
+++ b/lang/en.yml
@@ -54,7 +54,6 @@ en:
     DEFAULT: 'Default value'
     DEFAULTTOTODAY: 'Default to Today?'
     DISPLAYIF: 'Toggle visibility when'
-    DISPLAY_RULES_DISABLED: 'Display rules are not enabled for required fields. Please uncheck "Is this field Required?" under "Validation" to re-enable.'
     EXTRACLASS_MULTIPLE: 'Separate each CSS class with a single space'
     EXTRACLASS_SELECT: 'Select from the list of allowed styles'
     EXTRACLASS_TITLE: 'Extra Styling/Layout'
@@ -213,8 +212,6 @@ en:
     RANGE_TO: to
     SINGULARNAME: 'Text Field'
     TEXTLENGTH: 'Allowed text length'
-  SilverStripe\UserForms\Model\EditableFormField\Validator:
-    REQUIRED_ERROR: 'Form fields cannot be required and have conditional display rules.'
   SilverStripe\UserForms\Model\Recipient\EmailRecipient:
     CUSTOMRULESTAB: 'Custom Rules'
     EMAILCONTENTTAB: 'Email Content'
diff --git a/lang/eo.yml b/lang/eo.yml
index f03c97a..9f65d64 100644
--- a/lang/eo.yml
+++ b/lang/eo.yml
@@ -50,7 +50,10 @@ eo:
     DEFAULT: 'Apriora valoro'
     DEFAULTTOTODAY: 'Ĉu apriorie hodiaŭ?'
     DISPLAYIF: 'Baskuligi videblecon kiam'
-    DISPLAY_RULES_DISABLED: 'Vidigaj reguloj ne estas enŝaltitaj por bezonataj kampoj. Por reaktivigi ĝin, bonvolu malmarki "Ĉu ĉi tiu kampo estas bezonata?" sub "Validigo".'
+    DRAG: 'Ŝovi por rearanĝi kampojn'
+    ENTERQUESTION: 'Enigi demandon'
+    EXTRACLASSA: 'Ekstra stilado/aranĝado'
+    EXTRACLASSB: 'Ekstra css-klaso - apartigi opojn per spaceto'
     EXTRACLASS_MULTIPLE: 'Disigi ĉiun CSS-klason per unu spaceto'
     EXTRACLASS_SELECT: 'Elekti el la listo de eblaj stiloj'
     EXTRACLASS_TITLE: 'Ekstra stilado/aranĝado'
@@ -208,8 +211,6 @@ eo:
     RANGE_TO: al
     SINGULARNAME: 'Teksta kampo'
     TEXTLENGTH: 'Permesata longo de teksto'
-  SilverStripe\UserForms\Model\EditableFormField\Validator:
-    REQUIRED_ERROR: 'Formularaj kampoj ne povas esti nepraj kaj havi kondiĉajn vidigoregulojn.'
   SilverStripe\UserForms\Model\Recipient\EmailRecipient:
     CUSTOMRULESTAB: 'Propraj reguloj'
     EMAILCONTENTTAB: 'Retpoŝta enhavo'
diff --git a/lang/it.yml b/lang/it.yml
index 3693090..d1f19c2 100644
--- a/lang/it.yml
+++ b/lang/it.yml
@@ -27,7 +27,11 @@ it:
     CUSTOMRULES: 'Regole personalizzate'
     DEFAULT: 'Valore di default'
     DEFAULTTOTODAY: 'Di default a oggi?'
-    DISPLAY_RULES_DISABLED: 'Le regole di visualizzazione non sono attivate per i campi richiesti. Per piacere deseleziona "Questo campo è obbligatorio?" sotto "Validazione" per riabilitarle.'
+    DELETE: Elimina
+    DRAG: 'Trascina per riordinare l''ordine dei campi'
+    ENTERQUESTION: 'Inserisci la domanda'
+    EXTRACLASSA: 'Stile/Layout extra'
+    EXTRACLASSB: 'Classe CSS extra - separa valori multipli con uno spazio'
     EXTRACLASS_MULTIPLE: 'Separa ogni classe CSS con uno spazio singolo'
     EXTRACLASS_SELECT: 'Seleziona da una lista di stili consentiti'
     EXTRACLASS_TITLE: 'Stile/Layout extra'
@@ -116,8 +120,6 @@ it:
     RANGE_TO: a
     SINGULARNAME: 'Campo testo'
     TEXTLENGTH: 'Lunghezza testo consentita'
-  SilverStripe\UserForms\Model\EditableFormField\Validator:
-    REQUIRED_ERROR: 'I campi dei form non possono essere obbligatori e avere regole di visualizzazione condizionali.'
   SilverStripe\UserForms\Model\Recipient\EmailRecipient:
     CUSTOMRULESTAB: 'Regole personalizzate'
     EMAILCONTENTTAB: 'Contenuto dell''e-mail'
diff --git a/lang/sk.yml b/lang/sk.yml
index c27db30..c6e279f 100644
--- a/lang/sk.yml
+++ b/lang/sk.yml
@@ -27,7 +27,11 @@ sk:
     CUSTOMRULES: 'Vlastné pravidlá'
     DEFAULT: 'Predvolená hodnota'
     DEFAULTTOTODAY: 'Zobraziť v predvolenom režime na dnešný dátum?'
-    DISPLAY_RULES_DISABLED: 'Pravidlá zobrazenia nie sú povolené pre povinné/vyžadované polia. Prosím odškrtnite "Je pole povinné/vyžadované?" na záložke "Validácia".'
+    DELETE: Vymazať
+    DRAG: 'Ťahaním preskupiť poradie polí'
+    ENTERQUESTION: 'Zadajte otázku'
+    EXTRACLASSA: 'Extra úprava/vzhľad'
+    EXTRACLASSB: 'Extra CSS triedy - viaceré triedy oddeľujte medzerou'
     EXTRACLASS_MULTIPLE: 'Jednotlivé CSS triedy oddeľte jednou medzerou'
     EXTRACLASS_SELECT: 'Vyberte si zo zoznamu povolených štýlov'
     EXTRACLASS_TITLE: 'Extra úprava/vzhľad'
@@ -116,8 +120,6 @@ sk:
     RANGE_TO: do
     SINGULARNAME: 'Textové pole'
     TEXTLENGTH: 'Povolená dĺžka textu'
-  SilverStripe\UserForms\Model\EditableFormField\Validator:
-    REQUIRED_ERROR: 'Formulárové polia nemôžu byť vyžadované, ak majú podmienené pravidlá zobrazenia.'
   SilverStripe\UserForms\Model\Recipient\EmailRecipient:
     CUSTOMRULESTAB: 'Vlastné pravidlá'
     EMAILCONTENTTAB: 'Obsah e-mailu'
diff --git a/tests/Form/UserFormsRequiredFieldsTest.php b/tests/Form/UserFormsRequiredFieldsTest.php
new file mode 100644
index 0000000..9aae7be
--- /dev/null
+++ b/tests/Form/UserFormsRequiredFieldsTest.php
@@ -0,0 +1,147 @@
+<?php
+
+namespace SilverStripe\UserForms\Tests\Form;
+
+use SilverStripe\CMS\Controllers\ModelAsController;
+use SilverStripe\Dev\Debug;
+use SilverStripe\Dev\SapphireTest;
+use SilverStripe\UserForms\Form\UserFormsRequiredFields;
+use SilverStripe\UserForms\Model\UserDefinedForm;
+use SilverStripe\UserForms\Form\UserForm;
+
+class UserFormsRequiredFieldsTest extends SapphireTest
+{
+    protected static $fixture_file = '../UserFormsTest.yml';
+
+    private function getValidatorFromPage($page)
+    {
+        $controller = ModelAsController::controller_for($page);
+        $form = new UserForm($controller);
+        return $form->getValidator();
+    }
+
+    public function testUsesUserFormsRequiredFieldsValidator()
+    {
+        $page = $this->objFromFixture(UserDefinedForm::class, 'required-custom-rules-form');
+        $this->assertEquals(3, $page->Fields()->count());
+        $validator = $this->getValidatorFromPage($page);
+        $this->assertNotNull($validator);
+        $this->assertInstanceOf(UserFormsRequiredFields::class, $validator, 'Uses UserFormsRequiredFields validator');
+    }
+
+    public function dataProviderValidationOfConditionalRequiredFields()
+    {
+        return [
+            'Passes when non-conditional required field has a value' => [
+                [
+                    'required-text-field-2'     => 'some text',
+                    'radio-option-2'            => 'N',
+                    'conditional-required-text' => ''
+                ],
+                true
+            ],
+            'Fails when conditional required is displayed but not completed' => [
+                [
+                    'required-text-field-2'     => 'some text',
+                    'radio-option-2'            => 'Y',
+                    'conditional-required-text' => ''
+                ],
+                false
+            ],
+            'Passes when conditional required field has a value' => [
+                [
+                    'required-text-field-2'     => 'some text',
+                    'radio-option-2'            => 'Y',
+                    'conditional-required-text' => 'some more text'
+                ],
+                true
+            ]
+        ];
+    }
+
+    /**
+     * @param $data
+     * @param $expected
+     * @dataProvider dataProviderValidationOfConditionalRequiredFields
+     */
+    public function testValidationOfConditionalRequiredFields($data, $expected)
+    {
+        $page = $this->objFromFixture(UserDefinedForm::class, 'required-custom-rules-form');
+        $validator = $this->getValidatorFromPage($page);
+        $this->assertNotNull($validator);
+
+        $this->assertFalse(
+            $validator->php([]),
+            'Fails when non-conditional required field is empty'
+        );
+
+        $this->assertEquals($expected, $validator->php($data));
+    }
+
+    public function dataProviderValidationOfNestedConditionalRequiredFields()
+    {
+        return [
+            'Fails when non-conditional required field is empty' => [[], false],
+            'Passes when non-conditional required field has a value' => [
+                [
+                    'required-text-field-3'       => 'some text',
+                    'radio-option-3'              => 'N',
+                    'conditional-required-text-2' => '',
+                    'conditional-required-text-3' => ''
+                ],
+                true
+            ],
+            'Fails when conditional required is displayed but not completed' => [
+                [
+                    'required-text-field-3'       => 'some text',
+                    'radio-option-3'              => 'Y',
+                    'conditional-required-text-2' => '',
+                    'conditional-required-text-3' => ''
+                ],
+                false
+            ],
+            'Passes when non-conditional required field has a value' => [
+                [
+                    'required-text-field-3'       => 'some text',
+                    'radio-option-3'              => 'Y',
+                    'conditional-required-text-2' => 'this text',
+                    'conditional-required-text-3' => ''
+                ],
+                true
+            ],
+            'Fails when nested conditional required is displayed but not completed' => [
+                [
+                    'required-text-field-3'       => 'some text',
+                    'radio-option-3'              => 'Y',
+                    'conditional-required-text-2' => 'Show more',
+                    'conditional-required-text-3' => ''
+                ],
+                false
+            ],
+            'Passes when nested conditional required field has a value' => [
+                [
+                    'required-text-field-3'       => 'some text',
+                    'radio-option-3'              => 'Y',
+                    'conditional-required-text-2' => 'Show more',
+                    'conditional-required-text-3' => 'more text'
+                ],
+                true
+            ]
+        ];
+    }
+
+    /**
+     * @param string $data
+     * @param array $expected
+     * @dataProvider dataProviderValidationOfNestedConditionalRequiredFields
+     */
+    public function testValidationOfNestedConditionalRequiredFields($data, $expected)
+    {
+        $page = $this->objFromFixture(UserDefinedForm::class, 'required-nested-custom-rules-form');
+        $this->assertEquals(4, $page->Fields()->count());
+        $validator = $this->getValidatorFromPage($page);
+        $this->assertNotNull($validator);
+
+        $this->assertEquals($expected, $validator->php($data));
+    }
+}
diff --git a/tests/FormField/UserFormsCheckboxSetFieldTest.php b/tests/FormField/UserFormsCheckboxSetFieldTest.php
index 58aefed..dba5332 100644
--- a/tests/FormField/UserFormsCheckboxSetFieldTest.php
+++ b/tests/FormField/UserFormsCheckboxSetFieldTest.php
@@ -3,7 +3,7 @@
 namespace SilverStripe\UserForms\Tests\FormField;
 
 use SilverStripe\Dev\SapphireTest;
-use SilverStripe\Forms\RequiredFields;
+use SilverStripe\UserForms\Form\UserFormsRequiredFields;
 use SilverStripe\UserForms\FormField\UserFormsCheckboxSetField;
 
 class UserFormsCheckboxSetFieldTest extends SapphireTest
@@ -11,7 +11,7 @@ class UserFormsCheckboxSetFieldTest extends SapphireTest
     public function testValidate()
     {
         $field = new UserFormsCheckboxSetField('Field', 'My field', ['One' => 'One', 'Two' => 'Two']);
-        $validator = new RequiredFields();
+        $validator = new UserFormsRequiredFields();
 
         // String values
         $field->setValue('One');
diff --git a/tests/Model/EditableCustomRuleTest.php b/tests/Model/EditableCustomRuleTest.php
index 3d08d9a..c87b949 100644
--- a/tests/Model/EditableCustomRuleTest.php
+++ b/tests/Model/EditableCustomRuleTest.php
@@ -60,4 +60,86 @@ class EditableCustomRuleTest extends SapphireTest
         $this->assertSame('userform.field.show', $rule1->toggleDisplayEvent('show', true));
         $this->assertSame('userform.field.hide', $rule1->toggleDisplayEvent('hide', true));
     }
+
+    public function dataProviderValidateAgainstFormData()
+    {
+        return [
+            'IsNotBlank with blank value' =>
+                ['IsNotBlank', '', '', false],
+            'IsNotBlank with nopn-blank value' =>
+                ['IsNotBlank', '', 'something', true],
+            'IsBlank with blank value' =>
+                ['IsBlank', '', '', true],
+            'IsBlank with nopn-blank value' =>
+                ['IsBlank', '', 'something', false],
+            'HasValue with blank value' =>
+                ['HasValue', 'NZ', '', false],
+            'HasValue with correct value' =>
+                ['HasValue', 'NZ', 'NZ', true],
+            'HasValue with incorrect value' =>
+                ['HasValue', 'NZ', 'UK', false],
+            'ValueNot with blank value' =>
+                ['ValueNot', 'NZ', '', true],
+            'ValueNot with targeted value' =>
+                ['ValueNot', 'NZ', 'NZ', false],
+            'ValueNot with non-targeted value' =>
+                ['ValueNot', 'NZ', 'UK', true],
+            'ValueLessThan with value below target' =>
+                ['ValueLessThan', '0', '-0.00001', true],
+            'ValueLessThan with value equal to target' =>
+                ['ValueLessThan', '0', '0', false],
+            'ValueLessThan with value greater to target' =>
+                ['ValueLessThan', '0', '0.0001', false],
+            'ValueLessThanEqual with value below target' =>
+                ['ValueLessThanEqual', '0', '-0.00001', true],
+            'ValueLessThanEqual with value equal to target' =>
+                ['ValueLessThanEqual', '0', '0', true],
+            'ValueLessThanEqual with value greater to target' =>
+                ['ValueLessThanEqual', '0', '0.0001', false],
+            'ValueGreaterThan with value below target' =>
+                ['ValueGreaterThan', '0', '-0.00001', false],
+            'ValueGreaterThan with value equal to target' =>
+                ['ValueGreaterThan', '0', '0', false],
+            'ValueGreaterThan with value greater to target' =>
+                ['ValueGreaterThan', '0', '0.0001', true],
+            'ValueGreaterThanEqual with value below target' =>
+                ['ValueGreaterThanEqual', '0', '-0.00001', false],
+            'ValueGreaterThanEqual with value equal to target' =>
+                ['ValueGreaterThanEqual', '0', '0', true],
+            'ValueGreaterThanEqual with value greater to target' =>
+                ['ValueGreaterThanEqual', '0', '0.0001', true],
+        ];
+    }
+
+    /**
+     * Test that methods are returned for manipulating the presence of the "hide" CSS class depending
+     * on whether the field should be hidden or shown
+     * @dataProvider dataProviderValidateAgainstFormData
+     */
+    public function testValidateAgainstFormData($condition, $targetValue, $value, $expected)
+    {
+        $rule1 = $this->objFromFixture(EditableCustomRule::class, 'rule1');
+        $rule1->ConditionOption = $condition;
+        $rule1->FieldValue = $targetValue;
+
+        $this->assertFalse(
+            $rule1->validateAgainstFormData([]),
+            'Unset value always returns false no matter the rule'
+        );
+
+        $this->assertEquals(
+            $expected,
+            $rule1->validateAgainstFormData(['CountrySelection' => $value])
+        );
+    }
+
+    /**
+     * @expectedException LogicException
+     */
+    public function testValidateAgainstFormDataWithNonSenseRule()
+    {
+        $rule1 = $this->objFromFixture(EditableCustomRule::class, 'rule1');
+        $rule1->ConditionOption = 'NonSenseRule';
+        $rule1->validateAgainstFormData(['CountrySelection' => 'booya']);
+    }
 }
diff --git a/tests/Model/EditableFormFieldTest.php b/tests/Model/EditableFormFieldTest.php
index 595a340..a159384 100644
--- a/tests/Model/EditableFormFieldTest.php
+++ b/tests/Model/EditableFormFieldTest.php
@@ -72,6 +72,8 @@ class EditableFormFieldTest extends FunctionalTest
         // form has 2 fields - a checkbox and a text field
         // it has 1 rule - when ticked the checkbox hides the text field
         $this->assertEquals(1, $rules->Count());
+
+        // EffectiveDisplayRules rule has been deprecated
         $this->assertEquals($rules, $checkbox->EffectiveDisplayRules());
 
         $checkboxRule = $rules->First();
@@ -237,4 +239,57 @@ class EditableFormFieldTest extends FunctionalTest
 
         $this->assertContains('/images/editabletextfield.png', $field->getIcon());
     }
+
+    public function displayedProvider()
+    {
+        $one = ['basic_text_name' => 'foobar'];
+        $two = array_merge($one, ['basic_text_name_2' => 'foobar']);
+
+        return [
+            'no display rule AND' => ['alwaysVisible', [], true],
+            'no display rule OR' =>  ['alwaysVisibleOr', [], true],
+
+            'no display rule hidden AND' => ['neverVisible', [], false],
+            'no display rule hidden OR' => ['neverVisibleOr', [], false],
+
+            '1 unmet display rule AND' => ['singleDisplayRule', [], false],
+            '1 met display rule AND' => ['singleDisplayRule', $one, true],
+            '1 unmet display rule OR' => ['singleDisplayRuleOr', [], false],
+            '1 met display rule OR' => ['singleDisplayRuleOr', $one, true],
+
+            '1 unmet hide rule AND' => ['singleHiddingRule', [], true],
+            '1 met hide rule AND' => ['singleHiddingRule', $one, false],
+            '1 unmet hide rule OR' => ['singleHiddingRuleOr', [], true],
+            '1 met hide rule OR' => ['singleHiddingRuleOr', $one, false],
+
+            'multi display rule AND none met' => ['multiDisplayRule', [], false],
+            'multi display rule AND partially met' => ['multiDisplayRule', $one, false],
+            'multi display rule AND all met' => ['multiDisplayRule', $two, true],
+
+            'multi display rule OR none met' => ['multiDisplayRuleOr', [], false],
+            'multi display rule OR partially met' => ['multiDisplayRuleOr', $one, true],
+            'multi display rule OR all met' => ['multiDisplayRuleOr', $two, true],
+
+            'multi hide rule AND none met' => ['multiHiddingRule', [], true],
+            'multi hide rule AND partially met' => ['multiHiddingRule', $one, true],
+            'multi hide rule AND all met' => ['multiHiddingRule', $two, false],
+
+            'multi hide rule OR none met' => ['multiHiddingRuleOr', [], true],
+            'multi hide rule OR partially met' => ['multiHiddingRuleOr', $one, false],
+            'multi hide rule OR all met' => ['multiHiddingRuleOr', $two, false],
+        ];
+    }
+
+    /**
+     * @param $fieldName
+     * @param $data
+     * @param $expected
+     * @dataProvider displayedProvider
+     */
+    public function testIsDisplayed($fieldName, $data, $expected)
+    {
+        /** @var EditableFormField $field */
+        $field = $this->objFromFixture(EditableTextField::class, $fieldName);
+        $this->assertEquals($expected, $field->isDisplayed($data));
+    }
 }
diff --git a/tests/Model/EditableFormFieldTest.yml b/tests/Model/EditableFormFieldTest.yml
index b514964..d5f8695 100644
--- a/tests/Model/EditableFormFieldTest.yml
+++ b/tests/Model/EditableFormFieldTest.yml
@@ -4,7 +4,7 @@ SilverStripe\UserForms\Model\EditableFormField\EditableTextField:
     Title: Basic Text Field
 
   basic-text-2:
-    Name: basic_text_name
+    Name: basic_text_name_2
     Title: Basic Text Field
 
   required-text:
@@ -23,6 +23,83 @@ SilverStripe\UserForms\Model\EditableFormField\EditableTextField:
     DisplayRulesConjunction: And
     ShowOnLoad: false
 
+  # No rule
+  alwaysVisible:
+    Name: AlwaysVisible
+    Title: "This field is always visible"
+    ShowOnLoad: true
+    DisplayRulesConjunction: And
+
+  alwaysVisibleOr:
+    Name: AlwaysVisibleOr
+    Title: "This field is always visible"
+    ShowOnLoad: true
+    DisplayRulesConjunction: Or
+
+  neverVisible:
+    Name: NeverVisible
+    Title: "This field is never visible"
+    ShowOnLoad: false
+    DisplayRulesConjunction: And
+
+  neverVisibleOr:
+    Name: NeverVisibleOr
+    Title: "This field is never visible"
+    ShowOnLoad: false
+    DisplayRulesConjunction: Or
+
+  # Single rule
+
+  singleDisplayRule:
+    Name: SingleDisplayRule
+    Title: "This field will be displayed if the display rule is tripped"
+    ShowOnLoad: false
+    DisplayRulesConjunction: And
+
+  singleDisplayRuleOr:
+    Name: SingleDisplayRuleOr
+    Title: "This field will be displayed if the display rule is tripped"
+    ShowOnLoad: false
+    DisplayRulesConjunction: Or
+
+  singleHiddingRule:
+    Name: SingleHiddingRule
+    Title: "This field will be hidden if the display rule is tripped"
+    ShowOnLoad: true
+    DisplayRulesConjunction: And
+
+  singleHiddingRuleOr:
+    Name: SingleHiddingRuleOr
+    Title: "This field will be hidden if the display rule is tripped"
+    ShowOnLoad: true
+    DisplayRulesConjunction: Or
+
+  # Multi rule
+  multiDisplayRule:
+    Name: MultiDisplayRule
+    Title: "This field will be displayed if displayed if all the rule are met"
+    ShowOnLoad: false
+    DisplayRulesConjunction: And
+
+  multiDisplayRuleOr:
+    Name: MultiDisplayRuleOr
+    Title: "This field will be displayed if at least one rule is met"
+    ShowOnLoad: false
+    DisplayRulesConjunction: Or
+
+  multiHiddingRule:
+    Name: MultiHiddingRule
+    Title: "This field will be hidden if all the rule are met"
+    ShowOnLoad: true
+    DisplayRulesConjunction: And
+
+  multiHiddingRuleOr:
+    Name: MultiHiddingRuleOr
+    Title: "This field will be hidden if one rule is met"
+    ShowOnLoad: true
+    DisplayRulesConjunction: Or
+
+
 SilverStripe\UserForms\Model\EditableCustomRule:
   rule1:
     Display: Show
@@ -35,6 +112,66 @@ SilverStripe\UserForms\Model\EditableCustomRule:
     ConditionOption: HasValue
     FieldValue: 6
 
+  # Single rules
+  ruleSingleDisplay:
+    Display: Show
+    ConditionOption: IsNotBlank
+    ConditionField: =>SilverStripe\UserForms\Model\EditableFormField\EditableTextField.basic-text
+    Parent: =>SilverStripe\UserForms\Model\EditableFormField\EditableTextField.singleDisplayRule
+  ruleSingleDisplayOr:
+    Display: Show
+    ConditionOption: IsNotBlank
+    ConditionField: =>SilverStripe\UserForms\Model\EditableFormField\EditableTextField.basic-text
+    Parent: =>SilverStripe\UserForms\Model\EditableFormField\EditableTextField.singleDisplayRuleOr
+  ruleSingleHidding:
+    Display: Show
+    ConditionOption: IsNotBlank
+    ConditionField: =>SilverStripe\UserForms\Model\EditableFormField\EditableTextField.basic-text
+    Parent: =>SilverStripe\UserForms\Model\EditableFormField\EditableTextField.singleHiddingRule
+  ruleSingleHiddingOr:
+    Display: Show
+    ConditionOption: IsNotBlank
+    ConditionField: =>SilverStripe\UserForms\Model\EditableFormField\EditableTextField.basic-text
+    Parent: =>SilverStripe\UserForms\Model\EditableFormField\EditableTextField.singleHiddingRuleOr
+
+  # Multi rules
+  ruleMultiDisplay1:
+    ConditionOption: IsNotBlank
+    ConditionField: =>SilverStripe\UserForms\Model\EditableFormField\EditableTextField.basic-text
+    Parent: =>SilverStripe\UserForms\Model\EditableFormField\EditableTextField.multiDisplayRule
+  ruleMultiDisplay2:
+    ConditionOption: IsNotBlank
+    ConditionField: =>SilverStripe\UserForms\Model\EditableFormField\EditableTextField.basic-text-2
+    Parent: =>SilverStripe\UserForms\Model\EditableFormField\EditableTextField.multiDisplayRule
+
+  ruleMultiDisplayOr1:
+    ConditionOption: IsNotBlank
+    ConditionField: =>SilverStripe\UserForms\Model\EditableFormField\EditableTextField.basic-text
+    Parent: =>SilverStripe\UserForms\Model\EditableFormField\EditableTextField.multiDisplayRuleOr
+  ruleMultiDisplayOr2:
+    ConditionOption: IsNotBlank
+    ConditionField: =>SilverStripe\UserForms\Model\EditableFormField\EditableTextField.basic-text-2
+    Parent: =>SilverStripe\UserForms\Model\EditableFormField\EditableTextField.multiDisplayRuleOr
+
+
+  ruleMultiHidding1:
+    ConditionOption: IsNotBlank
+    ConditionField: =>SilverStripe\UserForms\Model\EditableFormField\EditableTextField.basic-text
+    Parent: =>SilverStripe\UserForms\Model\EditableFormField\EditableTextField.multiHiddingRule
+  ruleMultiHidding2:
+    ConditionOption: IsNotBlank
+    ConditionField: =>SilverStripe\UserForms\Model\EditableFormField\EditableTextField.basic-text-2
+    Parent: =>SilverStripe\UserForms\Model\EditableFormField\EditableTextField.multiHiddingRule
+
+  ruleMultiHiddingOr1:
+    ConditionOption: IsNotBlank
+    ConditionField: =>SilverStripe\UserForms\Model\EditableFormField\EditableTextField.basic-text
+    Parent: =>SilverStripe\UserForms\Model\EditableFormField\EditableTextField.multiHiddingRuleOr
+  ruleMultiHiddingOr2:
+    ConditionOption: IsNotBlank
+    ConditionField: =>SilverStripe\UserForms\Model\EditableFormField\EditableTextField.basic-text-2
+    Parent: =>SilverStripe\UserForms\Model\EditableFormField\EditableTextField.multiHiddingRuleOr
+
 SilverStripe\UserForms\Model\EditableFormField\EditableOption:
   option-1:
     Name: Option1
diff --git a/tests/UserFormsTest.yml b/tests/UserFormsTest.yml
index 9098845..f0d6871 100644
--- a/tests/UserFormsTest.yml
+++ b/tests/UserFormsTest.yml
@@ -61,6 +61,26 @@ SilverStripe\UserForms\Model\EditableFormField\EditableOption:
     Name: Option9
     Title: Green
 
+  option-y:
+    Name: option-y
+    Title: Yes
+    Value: Y
+
+  option-n:
+    Name: option-n
+    Title: No
+    Value: N
+
+  option-y-2:
+    Name: option-y-2
+    Title: Yes
+    Value: Y
+
+  option-n-2:
+    Name: option-n-2
+    Title: No
+    Value: N
+
 SilverStripe\UserForms\Model\EditableFormField\EditableTextField:
   basic-text:
     Name: basic_text_name
@@ -92,6 +112,38 @@ SilverStripe\UserForms\Model\EditableFormField\EditableTextField:
     CustomErrorMessage: Custom Error Message
     Required: true
 
+  required-text-2:
+    Name: required-text-field-2
+    Title: Required Text Field 2
+    Required: true
+
+  required-text-3:
+    Name: required-text-field-3
+    Title: Required Text Field 3
+    Required: true
+
+  conditional-required-text:
+    Name: conditional-required-text
+    Title: Conditional Required Text Field
+    CustomErrorMessage: Custom Error Message
+    Required: true
+    DisplayRulesConjunction: Or
+    ShowOnLoad: false
+
+  conditional-required-text-2:
+    Name: conditional-required-text-2
+    Title: Conditional Required Text Field 2
+    Required: true
+    DisplayRulesConjunction: Or
+    ShowOnLoad: false
+
+  conditional-required-text-3:
+    Name: conditional-required-text-3
+    Title: Conditional Required Text Field 3
+    Required: true
+    DisplayRulesConjunction: Or
+    ShowOnLoad: false
+
   field-1:
     Name: Field1
 
@@ -141,6 +193,14 @@ SilverStripe\UserForms\Model\EditableFormField\EditableCheckbox:
     Name: checkbox-1
     Title: Checkbox 1
 
+  checkbox-3:
+    Name: checkbox-3
+    Title: Checkbox 3
+
+  checkbox-4:
+    Name: checkbox-4
+    Title: Checkbox 4
+
 SilverStripe\UserForms\Model\EditableFormField\EditableCheckboxGroupField:
   checkbox-group:
     Name: check-box-group
@@ -174,6 +234,18 @@ SilverStripe\UserForms\Model\EditableFormField\EditableRadioField:
     Options:
       - =>SilverStripe\UserForms\Model\EditableFormField\EditableOption.option-5
       - =>SilverStripe\UserForms\Model\EditableFormField\EditableOption.option-6
+  radio-field-2:
+    Name: radio-option-2
+    Title: Radio Option 2
+    Options:
+      - =>SilverStripe\UserForms\Model\EditableFormField\EditableOption.option-y
+      - =>SilverStripe\UserForms\Model\EditableFormField\EditableOption.option-n
+  radio-field-3:
+    Name: radio-option-3
+    Title: Radio Option 3
+    Options:
+      - =>SilverStripe\UserForms\Model\EditableFormField\EditableOption.option-y-2
+      - =>SilverStripe\UserForms\Model\EditableFormField\EditableOption.option-n-2
 
 SilverStripe\UserForms\Model\EditableFormField\EditableFieldGroupEnd:
   group1end:
@@ -308,6 +380,21 @@ SilverStripe\UserForms\Model\UserDefinedForm:
       - =>SilverStripe\UserForms\Model\EditableFormField\EditableCheckbox.checkbox-2
       - =>SilverStripe\UserForms\Model\EditableFormField\EditableTextField.basic-text-2
 
+  required-custom-rules-form:
+    Title: Required Custom Rules Form
+    Fields:
+      - =>SilverStripe\UserForms\Model\EditableFormField\EditableTextField.required-text-2
+      - =>SilverStripe\UserForms\Model\EditableFormField\EditableRadioField.radio-field-2
+      - =>SilverStripe\UserForms\Model\EditableFormField\EditableTextField.conditional-required-text
+
+  required-nested-custom-rules-form:
+    Title: Required Nested Custom Rules Form
+    Fields:
+      - =>SilverStripe\UserForms\Model\EditableFormField\EditableTextField.required-text-3
+      - =>SilverStripe\UserForms\Model\EditableFormField\EditableRadioField.radio-field-3
+      - =>SilverStripe\UserForms\Model\EditableFormField\EditableTextField.conditional-required-text-2
+      - =>SilverStripe\UserForms\Model\EditableFormField\EditableTextField.conditional-required-text-3
+
   summary-rules-form:
     Title: Summary Fields Form
     Fields:
@@ -349,3 +436,23 @@ SilverStripe\UserForms\Model\UserDefinedForm:
     Title: Form with MultipleOption fields
     Fields:
       - =>SilverStripe\UserForms\Model\EditableFormField\EditableDropdown.basic-dropdown
+
+SilverStripe\UserForms\Model\EditableCustomRule:
+  rule1:
+    Display: Show
+    ConditionOption: HasValue
+    FieldValue: 'Y'
+    ConditionField: =>SilverStripe\UserForms\Model\EditableFormField\EditableRadioField.radio-field-2
+    Parent: =>SilverStripe\UserForms\Model\EditableFormField\EditableTextField.conditional-required-text
+  rule2:
+    Display: Show
+    ConditionOption: HasValue
+    FieldValue: 'Y'
+    ConditionField: =>SilverStripe\UserForms\Model\EditableFormField\EditableRadioField.radio-field-3
+    Parent: =>SilverStripe\UserForms\Model\EditableFormField\EditableTextField.conditional-required-text-2
+  rule3:
+    Display: Show
+    ConditionOption: HasValue
+    FieldValue: 'Show more'
+    ConditionField: =>SilverStripe\UserForms\Model\EditableFormField\EditableTextField.conditional-required-text-2
+    Parent: =>SilverStripe\UserForms\Model\EditableFormField\EditableTextField.conditional-required-text-3