diff --git a/app/controllers/admin/content_modules/games_controller.rb b/app/controllers/admin/content_modules/games_controller.rb
new file mode 100644
index 0000000..82f917c
--- /dev/null
+++ b/app/controllers/admin/content_modules/games_controller.rb
@@ -0,0 +1,33 @@
+class Admin::ContentModules::GamesController < AdminController
+  before_action :set_content_module
+
+  def new
+    @content = @content_module.contents.build
+    load_game_options
+  end
+
+  def create
+    @content = @content_module.contents.build(contentable: Game.find_by(id: content_params[:contentable_id]))
+
+    if @content.save
+      redirect_to edit_admin_content_module_path(@content_module), notice: "Game was successfully added."
+    else
+      load_game_options
+      render :new, status: :unprocessable_entity
+    end
+  end
+
+  private
+    def set_content_module
+      @content_module = ContentModule.find(params.expect(:content_module_id))
+    end
+
+    def load_game_options
+      @available_games = Game.available_for(@content_module)
+      @any_games = Game.exists?
+    end
+
+    def content_params
+      params.expect(content: [ :contentable_id ])
+    end
+end
diff --git a/app/views/admin/content_modules/edit.html.erb b/app/views/admin/content_modules/edit.html.erb
index cfe4a6f..6f47207 100644
--- a/app/views/admin/content_modules/edit.html.erb
+++ b/app/views/admin/content_modules/edit.html.erb
@@ -23,6 +23,7 @@
         <div class="flex justify-between items-center mb-2 gap-2 flex-wrap">
           <h2 class="card-title text-lg">Contents</h2>
           <div class="flex items-center gap-2">
+            <%= link_to "Add game", new_admin_content_module_game_path(@content_module), class: "btn btn-sm btn-primary" %>
             <%= link_to "Add link", new_admin_content_module_link_path(@content_module), class: "btn btn-sm btn-primary" %>
           </div>
         </div>
diff --git a/app/views/admin/content_modules/games/new.html.erb b/app/views/admin/content_modules/games/new.html.erb
new file mode 100644
index 0000000..92be4f4
--- /dev/null
+++ b/app/views/admin/content_modules/games/new.html.erb
@@ -0,0 +1,45 @@
+<% content_for :title, "Add Game" %>
+
+<nav class="breadcrumbs text-sm">
+  <ul>
+    <li><%= link_to "Content Modules", admin_content_modules_path %></li>
+    <li><%= link_to @content_module.name, edit_admin_content_module_path(@content_module) %></li>
+    <li>Add Game</li>
+  </ul>
+</nav>
+<section class="py-10 flex items-center justify-center">
+  <div class="card card-border bg-base-100 shadow-md w-96">
+    <div class="card-body">
+      <h1 class="card-title">Add Game</h1>
+      <% if @available_games.any? %>
+        <%= form_with model: @content, url: admin_content_module_games_path(@content_module) do |form| %>
+          <div class="flex flex-col gap-2">
+            <% if @content.errors.any? %>
+              <div style="color: red">
+                <h2><%= pluralize(@content.errors.count, "error") %> prohibited this game from being added:</h2>
+                <ul>
+                  <% @content.errors.each do |error| %>
+                    <li><%= error.full_message %></li>
+                  <% end %>
+                </ul>
+              </div>
+            <% end %>
+
+            <%= form.label :contentable_id, "Game", class: "label" %>
+            <%= form.collection_select :contentable_id, @available_games, :id, :title,
+                  { include_blank: "Select a game" }, class: "select w-full" %>
+            <%= form.submit "Add game", class: "btn btn-primary" %>
+          </div>
+        <% end %>
+      <% elsif @any_games %>
+        <p class="text-sm opacity-60">All games are in this module.</p>
+      <% else %>
+        <p class="text-sm opacity-60">
+          No games yet.
+          <%= link_to "Create a game", new_admin_game_path, class: "link" %>
+        </p>
+      <% end %>
+      <%= link_to "Back to module", edit_admin_content_module_path(@content_module), class: "link text-sm" %>
+    </div>
+  </div>
+</section>
diff --git a/config/locales/en.yml b/config/locales/en.yml
index 6c349ae..ed89ef2 100644
--- a/config/locales/en.yml
+++ b/config/locales/en.yml
@@ -29,3 +29,8 @@
 
 en:
   hello: "Hello world"
+  activerecord:
+    attributes:
+      content:
+        contentable: "Game"
+        contentable_id: "Game"
diff --git a/config/routes.rb b/config/routes.rb
index b5269d3..923338e 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -24,6 +24,7 @@
     end
     resources :content_modules, except: [ :show ] do
       resources :links, shallow: true, except: %i[index show destroy]
+      resources :games, only: %i[new create], module: :content_modules
       resources :contents, shallow: true, only: :destroy
     end
     resources :classroom_modules, only: %i[update]
diff --git a/test/controllers/admin/content_modules/games_controller_test.rb b/test/controllers/admin/content_modules/games_controller_test.rb
new file mode 100644
index 0000000..6a3daf0
--- /dev/null
+++ b/test/controllers/admin/content_modules/games_controller_test.rb
@@ -0,0 +1,107 @@
+require "test_helper"
+
+class Admin::ContentModules::GamesControllerTest < ActionDispatch::IntegrationTest
+  setup do
+    @content_module = ContentModule.create! name: "Module", program: programs(:one), level: :basic
+    sign_in_as users(:one)
+  end
+
+  test "new offers only games not yet in the module" do
+    @content_module.contents.create! contentable: games(:one)
+    expected_games = Game.all - [ games(:one) ]
+
+    get new_admin_content_module_game_url(@content_module)
+
+    assert_response :success
+    assert_select "form[action='#{admin_content_module_games_path(@content_module)}']" do
+      expected_games.each do |game|
+        assert_select "select[name='content[contentable_id]'] option", text: game.title, count: 1
+      end
+      assert_select "select[name='content[contentable_id]'] option", text: games(:one).title, count: 0
+    end
+  end
+
+  test "new offers a blank select a game option" do
+    get new_admin_content_module_game_url(@content_module)
+
+    assert_select "select[name='content[contentable_id]'] option[value='']", text: "Select a game"
+  end
+
+  test "new explains when every game is attached" do
+    Game.all.each { |game| @content_module.contents.create! contentable: game }
+
+    get new_admin_content_module_game_url(@content_module)
+
+    assert_response :success
+    assert_select "select[name='content[contentable_id]']", count: 0
+    assert_select "p", text: /All games are in this module\./
+    assert_select "a[href='#{edit_admin_content_module_path(@content_module)}']"
+  end
+
+  test "new links to creating a game when no games exist" do
+    Game.destroy_all
+
+    get new_admin_content_module_game_url(@content_module)
+
+    assert_response :success
+    assert_select "select[name='content[contentable_id]']", count: 0
+    assert_select "p", text: /No games yet/
+    assert_select "a.link[href='#{new_admin_game_path}']", text: "Create a game"
+  end
+
+  test "new requires admin sign in" do
+    sign_out
+
+    get new_admin_content_module_game_url(@content_module)
+
+    assert_redirected_to new_admin_session_url
+  end
+
+  test "create attaches an existing game to the module" do
+    game = games(:one)
+
+    assert_difference -> { @content_module.contents.count }, 1 do
+      post admin_content_module_games_url(@content_module), params: { content: { contentable_id: game.id } }
+    end
+
+    assert_redirected_to edit_admin_content_module_url(@content_module)
+    assert_equal game, @content_module.contents.last.contentable
+  end
+
+  test "create does not attach the same game twice" do
+    @content_module.contents.create! contentable: games(:one)
+    assert_no_difference "Content.count" do
+      post admin_content_module_games_url(@content_module), params: { content: { contentable_id: games(:one).id } }
+    end
+
+    assert_response :unprocessable_entity
+    assert_select "li", text: "Game is already in this module"
+  end
+
+  test "create asks for a game when none is selected" do
+    assert_no_difference "Content.count" do
+      post admin_content_module_games_url(@content_module), params: { content: { contentable_id: "" } }
+    end
+
+    assert_response :unprocessable_entity
+    assert_select "li", text: "Game must exist"
+  end
+
+  test "create asks for a game when the game is unknown" do
+    assert_no_difference "Content.count" do
+      post admin_content_module_games_url(@content_module), params: { content: { contentable_id: 0 } }
+    end
+
+    assert_response :unprocessable_entity
+    assert_select "li", text: "Game must exist"
+  end
+
+  test "create requires admin sign in" do
+    sign_out
+
+    assert_no_difference "Content.count" do
+      post admin_content_module_games_url(@content_module), params: { content: { contentable_id: games(:two).id } }
+    end
+    assert_redirected_to new_admin_session_url
+  end
+end
diff --git a/test/models/content_module_test.rb b/test/models/content_module_test.rb
index 7d8f697..ba04dde 100644
--- a/test/models/content_module_test.rb
+++ b/test/models/content_module_test.rb
@@ -39,9 +39,10 @@ class ContentModuleTest < ActiveSupport::TestCase
   test "returns contents ordered by position" do
     content_module = create_module("With Contents")
     first, second = [
-      content_module.contents.create!(contentable: games(:one), position: 1),
-      content_module.contents.create!(contentable: games(:two), position: 2)
+      content_module.contents.create!(contentable: games(:one)),
+      content_module.contents.create!(contentable: games(:two))
     ]
+    second.move_up
     assert_equal [ second, first ], content_module.contents.to_a
   end