diff --git a/.rubocop.yml b/.rubocop.yml
index bede808..2ad2401 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -41,7 +41,7 @@ Style/StringLiterals:
 Metrics/AbcSize:
   Exclude:
     - db/migrate/**/*
-  Max: 18
+  Max: 20
 
 Metrics/LineLength:
   Max: 110
diff --git a/app/controllers/candidate_controller.rb b/app/controllers/candidate_controller.rb
index 0daca3d..051b1ae 100644
--- a/app/controllers/candidate_controller.rb
+++ b/app/controllers/candidate_controller.rb
@@ -13,8 +13,7 @@ class CandidateController < ApplicationController
   end
 
   def question
-    @status = QuizStatus.new(current_candidate)
-    qid = @status.current_question_id
+    qid = prep_status.current_question_id
 
     redirect_to :summary and return if qid.nil?
 
@@ -29,9 +28,8 @@ class CandidateController < ApplicationController
 
   def summary
     @quiz = current_candidate.my_quiz
-    @status = QuizStatus.new(current_candidate)
 
-    redirect_to :question and return unless @status.current_question_id.nil?
+    redirect_to :question and return unless prep_status.current_question_id.nil?
   end
 
   def update_text
@@ -39,7 +37,7 @@ class CandidateController < ApplicationController
     @answer.update(answer: answer_params[:text],
                    saved: answer_params[:save],
                    submitted: answer_params[:next])
-    validate_answer
+    route_answer
   end
 
   def update_radio
@@ -47,7 +45,7 @@ class CandidateController < ApplicationController
     @answer.update(answer: answer_params[:radio],
                    saved: answer_params[:save],
                    submitted: answer_params[:next])
-    validate_answer
+    route_answer
   end
 
   def update_checkbox
@@ -55,7 +53,7 @@ class CandidateController < ApplicationController
     @answer.update(answer: answer_params[:checkbox],
                    saved: answer_params[:save],
                    submitted: answer_params[:next])
-    validate_answer
+    route_answer
   end
 
   def update_live_code
@@ -63,7 +61,7 @@ class CandidateController < ApplicationController
     @answer.update(answer: answer_params[:live_code],
                    saved: answer_params[:save],
                    submitted: answer_params[:next])
-    validate_answer
+    route_answer
   end
 
   # TODO
@@ -86,6 +84,10 @@ class CandidateController < ApplicationController
       @question = current_candidate.fetch_question(qid)
     end
 
+    def prep_status
+      @status ||= QuizStatus.new(current_candidate)
+    end
+
     def answer_params
       params.require(:answer).permit(
         :question_id, :answer_id,
@@ -100,10 +102,11 @@ class CandidateController < ApplicationController
       answer
     end
 
-    def validate_answer
+    def route_answer
       if @answer.errors.present?
-        flash[:error] = [answer_params[:question_id]]
+        prep_status
         prep_question answer_params[:question_id]
+        flash[:answer_error] = answer_params[:question_id].to_i
         render :question
       else
         # TODO: change params.key? to submit = save/next/summary
diff --git a/app/models/answer.rb b/app/models/answer.rb
index 1d6ebf2..b1dc993 100644
--- a/app/models/answer.rb
+++ b/app/models/answer.rb
@@ -3,4 +3,8 @@ class Answer < ApplicationRecord
 
   belongs_to :question
   belongs_to :candidate
+
+  validates :candidate_id, presence: true
+  validates :question_id, presence: true
+  validates :answer, answer_format: true
 end
diff --git a/app/validators/answer_format_validator.rb b/app/validators/answer_format_validator.rb
new file mode 100644
index 0000000..32f0a3f
--- /dev/null
+++ b/app/validators/answer_format_validator.rb
@@ -0,0 +1,38 @@
+class AnswerFormatValidator < ActiveModel::EachValidator
+  def validate_each(record, attribute, value)
+    send(record.question.input_type, record, attribute, value)
+  end
+
+  private
+
+    def text record, attribute, value
+      return unless value.length.between? 1, 1000
+
+      if value.blank?
+        record.errors[attribute] << (options[:message] || "Please enter an answer.")
+      end
+
+      if value.length > 1000
+        record.errors[attribute] << (options[:message] || "The character limit for a textarea answer is 1000")
+      end
+    end
+
+    def radio record, attribute, value
+      return unless value.nil?
+
+      record.errors[attribute] << (options[:message] || "Please select an answer.")
+    end
+
+    def checkbox record, attribute, value
+      return unless value.nil? || value.join.blank?
+
+      record.errors[attribute] << (options[:message] || "Please select an answer.")
+    end
+
+    def live_code record, attribute, value
+      return unless value.nil?
+
+      msg = "You must write code in one of the above textareas to progress."
+      record.errors[attribute] << (options[:message] || msg)
+    end
+end
diff --git a/app/views/candidate/_answer_errors.html.erb b/app/views/candidate/_answer_errors.html.erb
new file mode 100644
index 0000000..b69a5f1
--- /dev/null
+++ b/app/views/candidate/_answer_errors.html.erb
@@ -0,0 +1,5 @@
+<% if flash[:answer_error] == question.question_id %>
+  <% answer.errors.messages[:answer].each do |message| %>
+    <div class="error"><%= message %></div>
+  <% end %>
+<% end %>
diff --git a/app/views/candidate/_checkbox.html.erb b/app/views/candidate/_checkbox.html.erb
index ca06c9b..ad86f2a 100644
--- a/app/views/candidate/_checkbox.html.erb
+++ b/app/views/candidate/_checkbox.html.erb
@@ -14,6 +14,4 @@
   </div>
 <% end %>
 
-<% if flash[:error].try(:include?, question.to_i) %>
-  <div class="error">Please select an answer.</div>
-<% end %>
+<%= render partial: "candidate/answer_errors", locals: {question: question, answer: @answer} %>
diff --git a/app/views/candidate/_radio.html.erb b/app/views/candidate/_radio.html.erb
index 38a8bbd..3d1cd7d 100644
--- a/app/views/candidate/_radio.html.erb
+++ b/app/views/candidate/_radio.html.erb
@@ -9,6 +9,4 @@
   </div>
 <% end %>
 
-<% if flash[:error].try(:include?, question.to_i) %>
-  <div class="error">Please select an answer.</div>
-<% end %>
+<%= render partial: "candidate/answer_errors", locals: {question: question, answer: @answer} %>
diff --git a/app/views/candidate/_text.html.erb b/app/views/candidate/_text.html.erb
index db29ee0..d910317 100644
--- a/app/views/candidate/_text.html.erb
+++ b/app/views/candidate/_text.html.erb
@@ -3,6 +3,4 @@
 
 <div class="chars">Characters remaining: <span></span></div>
 
-<% if flash[:error].try(:include?, question.to_i) %>
-  <div class="error">Please select or enter an answer. (The character limit for a textarea answer is 1000)</div>
-<% end %>
+<%= render partial: "candidate/answer_errors", locals: {question: question, answer: @answer} %>
diff --git a/app/views/candidate/live_code.html.erb b/app/views/candidate/live_coder.html.erb
similarity index 80%
rename from app/views/candidate/live_code.html.erb
rename to app/views/candidate/live_coder.html.erb
index 331e3e0..4a5c2bb 100644
--- a/app/views/candidate/live_code.html.erb
+++ b/app/views/candidate/live_coder.html.erb
@@ -13,8 +13,6 @@
   <textarea data-id="code-js" name="code-js" class="code-answer code-js"><%= @answer['js'] unless @answer.nil? %></textarea>
 </div>
 
-<% if flash[:error].try(:include?, @question.to_i) %>
-  <div class="error">You must write code in one of the above textareas to progress.</div>
-<% end %>
+<%= render partial: "candidate/answer_errors", locals: {question: question, answer: @answer} %>
 
 <div class="results" data-id="results"></div>
diff --git a/config/initializers/custom_error_wrapper.rb b/config/initializers/custom_error_wrapper.rb
new file mode 100644
index 0000000..67cc908
--- /dev/null
+++ b/config/initializers/custom_error_wrapper.rb
@@ -0,0 +1,5 @@
+# TODO: needs better wrapping instead of nuking
+# https://rubyplus.com/articles/3401
+ActionView::Base.field_error_proc = proc do |html_tag, _instance|
+  html_tag.html_safe
+end
diff --git a/test/controllers/candidate_controller_test.rb b/test/controllers/candidate_controller_test.rb
index aab1e34..3df9b82 100644
--- a/test/controllers/candidate_controller_test.rb
+++ b/test/controllers/candidate_controller_test.rb
@@ -50,5 +50,13 @@ class CandidateControllerTest < ActionDispatch::IntegrationTest
     assert_response :success
   end
 
-  # should get flash message on bad question
+  test "should get flash message on bad radio response" do
+    setup_auth candidates(:martha)
+    qid = questions(:fed1).id
+    post post_radio_url, params: { answer: { question_id: qid, radio: nil } }
+
+    assert_response :success
+    assert session[:test_id].present?
+    assert_equal qid, flash[:answer_error]
+  end
 end