diff --git a/packages/server/src/messages/start.ts b/packages/server/src/messages/start.ts
index 280bce92..12f67edd 100644
--- a/packages/server/src/messages/start.ts
+++ b/packages/server/src/messages/start.ts
@@ -6,6 +6,7 @@ import { logs } from "../logs.js"
 import { Player } from "../player/player.js"
 import type { Room } from "../room/base.js"
 import type { State } from "../state/state.js"
+import { variantParser } from "../utils/variantParser.js"
 
 /**
  * @param this
@@ -42,9 +43,19 @@ export function start(
       return
     }
     if (variantData) {
-      if (variantsConfig.parse) {
-        variantData = variantsConfig.parse(variantData)
+      try {
+        if (variantsConfig.parse) {
+          variantData = variantsConfig.parse(variantData)
+        } else {
+          variantData = variantParser(variantData)
+        }
+      } catch (e) {
+        client?.send("gameError", {
+          data: "Game room setup config parsing failed. " + e.message,
+        })
+        return
       }
+
       const validationResults = variantsConfig.validate?.(variantData)
 
       if (validationResults !== true) {
diff --git a/packages/server/src/room/base.ts b/packages/server/src/room/base.ts
index 30f4f2e0..5f0a6e4a 100644
--- a/packages/server/src/room/base.ts
+++ b/packages/server/src/room/base.ts
@@ -19,7 +19,6 @@ import type { Player, ServerPlayerMessage, Bot } from "../player/index.js"
 import { State } from "../state/state.js"
 import { debugRoomMessage } from "../utils/debugRoomMessage.js"
 
-import { VariantsConfig } from "./gameVariants.js"
 import type { RoomDefinition } from "./roomType.js"
 
 type BroadcastOptions = IBroadcastOptions & {
diff --git a/packages/server/src/room/index.ts b/packages/server/src/room/index.ts
index 4c759f79..fc5e7cea 100644
--- a/packages/server/src/room/index.ts
+++ b/packages/server/src/room/index.ts
@@ -1,4 +1,3 @@
 export { defineRoom, RoomConstructor } from "./defineRoom.js"
 export { Room } from "./base.js"
 export { RoomDefinition } from "./roomType.js"
-export { VariantsConfig } from "./gameVariants.js"
diff --git a/packages/server/src/room/roomType.ts b/packages/server/src/room/roomType.ts
index f682375d..36bc688f 100644
--- a/packages/server/src/room/roomType.ts
+++ b/packages/server/src/room/roomType.ts
@@ -6,7 +6,6 @@ import type { Player } from "../player/index.js"
 import type { State } from "../state/state.js"
 
 import type { Room } from "./base.js"
-import { VariantsConfig } from "./gameVariants.js"
 
 /**
  * Extracted from colyseus room, and suggesting.
diff --git a/packages/server/src/state/state.ts b/packages/server/src/state/state.ts
index b6c36702..6a2bf20f 100644
--- a/packages/server/src/state/state.ts
+++ b/packages/server/src/state/state.ts
@@ -6,7 +6,6 @@ import { containsChildren } from "../annotations/containsChildren.js"
 import { type } from "../annotations/type.js"
 import { Player } from "../player/player.js"
 import { PlayerViewPosition } from "../playerViewPosition.js"
-import { VariantsConfig } from "../room/gameVariants.js"
 import { applyTraitsMixins, Entity } from "../traits/entity.js"
 import { IdentityTrait } from "../traits/identity.js"
 import { LabelTrait } from "../traits/label.js"
diff --git a/packages/server/src/utils/__test__/variantParset.test.ts b/packages/server/src/utils/__test__/variantParset.test.ts
new file mode 100644
index 00000000..6092efea
--- /dev/null
+++ b/packages/server/src/utils/__test__/variantParset.test.ts
@@ -0,0 +1,17 @@
+import { variantParser } from "../variantParser.js"
+
+describe("deep object", () => {
+  it("parses single deep field", () => {
+    const data = {
+      "foo.bar": true,
+      "card.suit": "S",
+      "card.rank": "A",
+      first: 1,
+    }
+    const result = variantParser(data)
+    expect(result["foo"]["bar"]).toBe(true)
+    expect(result["card"]["suit"]).toBe("S")
+    expect(result["card"]["rank"]).toBe("A")
+    expect(result["first"]).toBe(1)
+  })
+})
diff --git a/packages/server/src/utils/variantParser.ts b/packages/server/src/utils/variantParser.ts
new file mode 100644
index 00000000..2baf427a
--- /dev/null
+++ b/packages/server/src/utils/variantParser.ts
@@ -0,0 +1,49 @@
+function deepAssign(
+  object: Record<string, any>,
+  path: string[],
+  value: unknown,
+): void {
+  if (path.length === 1) {
+    // as deep as it gets, set
+    object[path[0]] = value
+    return
+  }
+
+  const key = path.shift()
+
+  if (object[key] === undefined) {
+    object[key] = {}
+  } else if (typeof object[key] !== "object") {
+    throw new Error(
+      `Expected to access "${path.join(".")} but it's of type ${typeof object[
+        key
+      ]}"`,
+    )
+  }
+
+  deepAssign(object[key], path, value)
+}
+
+export const variantParser = <T extends Record<string, unknown>>(
+  value: unknown,
+): T => {
+  // Expected flat object of props. Possible sub objects with dot notation
+
+  if (typeof value !== "object") {
+    throw new Error("Variant data not an object, cannot parse")
+  }
+
+  const result = {}
+
+  Object.keys(value).forEach((key) => {
+    const isPath = key.includes("$")
+
+    if (!isPath) {
+      result[key] = value[key]
+    } else {
+      deepAssign(result, key.split("$"), value[key])
+    }
+  })
+
+  return result as T
+}
diff --git a/packages/types/src/index.d.ts b/packages/types/src/index.d.ts
index 61a0ab6d..8952cec3 100644
--- a/packages/types/src/index.d.ts
+++ b/packages/types/src/index.d.ts
@@ -1,6 +1,7 @@
 /// <reference path="cards.d.ts" />
 /// <reference path="messages.d.ts" />
 /// <reference path="utils.d.ts" />
+/// <reference path="variants.d.ts" />
 
 interface RoomCreateOptions {
   [key: string]: unknown
diff --git a/packages/server/src/room/gameVariants.ts b/packages/types/src/variants.d.ts
similarity index 78%
rename from packages/server/src/room/gameVariants.ts
rename to packages/types/src/variants.d.ts
index fb752458..07ea68e5 100644
--- a/packages/server/src/room/gameVariants.ts
+++ b/packages/types/src/variants.d.ts
@@ -1,11 +1,15 @@
-type VariantPreset<T> = {
+type VariantPreset<
+  T extends Record<string, unknown> = Record<string, unknown>,
+> = {
   name: string
   data: DeepPartial<T>
   /** Should this preset be merging with the defaults or not? */
   includesDefaults?: boolean
 }
 
-export type VariantsConfig<T> = {
+type VariantsConfig<
+  T extends Record<string, unknown> = Record<string, unknown>,
+> = {
   defaults: Required<T>
   /**
    * Decide how you want to send variant data from the client