diff --git a/hench.mjs b/hench.mjs
index 09da92e..97da6f6 100644
--- a/hench.mjs
+++ b/hench.mjs
@@ -1,6 +1,7 @@
 import { HenchCard, HenchCardDataModel } from "./module/cards/hench-card.mjs";
 import { HenchCards, HenchCardsDataModel } from "./module/cards/hench-cards.mjs";
 import { BossDataModel, HenchDataModel } from "./module/data-models.mjs";
+import { CURRENT_VERSION, showUpdateWarningDialogue } from "./module/helpers/update-helper.mjs";
 
 import { HenchActorSheet } from "./module/sheets/hench-actor-sheet.mjs";
 import { HenchCardsSheet } from "./module/sheets/hench-cards-sheet.mjs";
@@ -101,4 +102,24 @@ Hooks.once("init", () => {
     // remove other card stack types...
     CardStacks.unregisterSheet('core', CardsHand);
     CardStacks.unregisterSheet('core', CardsPile);
+
+    // prepare version checker
+    game.settings.register('hench', 'version', {
+        name: 'Version',
+        scope: 'world',
+        config: true,
+        type: String,
+    });
+});
+
+Hooks.once("ready", () => {
+    // update version and alert if updated
+    const existingVersion = game.settings.get('hench', 'version');
+    
+    // TODO: don't alert on null/undefined after draft 1 cut.
+    if(existingVersion !== CURRENT_VERSION) {
+        showUpdateWarningDialogue(existingVersion);
+    }
+
+    game.settings.set('hench', 'version', CURRENT_VERSION);
 });
\ No newline at end of file
diff --git a/module/helpers/update-helper.mjs b/module/helpers/update-helper.mjs
new file mode 100644
index 0000000..6854ba2
--- /dev/null
+++ b/module/helpers/update-helper.mjs
@@ -0,0 +1,72 @@
+export const versions = {
+    UNDEFINED: '',
+    DRAFT_0: '0',
+    DRAFT_1: '1',
+};
+
+export const CURRENT_VERSION = versions.DRAFT_1;
+
+const updateMap = {
+    [versions.UNDEFINED]: versions.DRAFT_0,
+    [versions.DRAFT_0]: versions.DRAFT_1,
+};
+
+const updateWarnings = {
+    [versions.DRAFT_1]: {
+        title: `Draft 1 Update!`,
+        content: `The module is now compatible with Draft 1. Due to these changes, we recommend:
+            <ul>
+                <li> You create new character sheets for Henches and Bosses, and delete the old ones. </li>
+                <li> You delete and recreate your deck, or update the Ace of Diamonds and add a joker. </li>
+            </ul>`,
+    },
+};
+
+function getWarningsSinceVersion(oldVersion) {
+    
+    const next_v = updateMap[oldVersion];
+
+    if(next_v) {
+        const next_w = updateWarnings[next_v];
+
+        if(next_w) {
+            return [...getWarningsSinceVersion(next_v), next_w];
+        } else {
+            return getWarningsSinceVersion(next_v);
+        }
+    } else {
+        return [];
+    }
+}
+
+export function showUpdateWarningDialogue(oldVersion) {
+    const warnings = getWarningsSinceVersion(oldVersion);
+
+    if(warnings?.length > 0) {
+        const header = ``;
+
+        const content = warnings.reduce((prev, next) => {
+            return prev + `
+                <div>
+                    <h2>${next.title}</h2>
+                    <p>${next.content}</p>
+                </div>`;
+        }, header);
+
+        const dialogue = new Dialog({
+            title: 'Update Notice',
+            content: content,
+            buttons: {
+                one: {
+                    label: 'OK',
+                    callback: () => null,
+                }
+            },
+            default: "one",
+        });
+
+        dialogue.render(true);
+
+        return dialogue;
+    }
+}
\ No newline at end of file