diff --git a/packages/game/package.json b/packages/game/package.json
index 7e6a856..5854459 100644
--- a/packages/game/package.json
+++ b/packages/game/package.json
@@ -6,5 +6,7 @@
   "scripts": {
     "build": "tsc -b"
   },
-  "dependencies": {}
+  "dependencies": {
+    "zod": "^3.23.8"
+  }
 }
diff --git a/packages/game/src/schema/condition.ts b/packages/game/src/schema/condition.ts
new file mode 100644
index 0000000..e69de29
diff --git a/packages/game/src/schema/index.ts b/packages/game/src/schema/index.ts
new file mode 100644
index 0000000..f21337b
--- /dev/null
+++ b/packages/game/src/schema/index.ts
@@ -0,0 +1,54 @@
+import { z } from 'zod'
+
+export const requirementsSchema = z.object({
+  requirements: z.array(z.string()),
+})
+
+export type IRequirements = z.infer<typeof requirementsSchema>
+
+export const fileInputSchema = z.object({
+  path: z.string(),
+  type: z.enum(['file', 'folder']),
+})
+
+export type IFileInput = z.infer<typeof fileInputSchema>
+
+export const fileExistenceInputSchema = fileInputSchema.extend({
+  exists: z.boolean(),
+})
+
+export type IFileExistenceInput = z.infer<typeof fileExistenceInputSchema>
+
+const baseConditionSchema = z.object({
+  command: z.string().optional(),
+  output: z.string().optional(),
+  error: z.string().optional(),
+  pwd: z.string().optional(),
+  files: z.array(fileExistenceInputSchema).optional(),
+})
+
+export type ICondition = z.infer<typeof baseConditionSchema> & {
+  or?: ICondition[]
+  not?: ICondition
+}
+
+export const conditionSchema: z.ZodType<ICondition> =
+  baseConditionSchema.extend({
+    or: z.lazy(() => z.array(conditionSchema)).optional(),
+    not: z.lazy(() => conditionSchema).optional(),
+  })
+
+export const responseSchema = z.object({
+  type: z.enum(['narrative', 'dialogue']),
+  content: z.string(),
+})
+
+export const stageSchema = z.object({
+  id: z.string().regex(/^[a-zA-Z0-9_-]+$/),
+  name: z.string().optional(),
+  requirements: z.array(z.string()),
+  condition: conditionSchema,
+  response: responseSchema,
+})
+
+export type IStage = z.infer<typeof stageSchema>
diff --git a/packages/game/src/schema/requirements.ts b/packages/game/src/schema/requirements.ts
new file mode 100644
index 0000000..e69de29
diff --git a/packages/game/src/schema/stage.ts b/packages/game/src/schema/stage.ts
new file mode 100644
index 0000000..e69de29
diff --git a/packages/game/test/condition.test.ts b/packages/game/test/condition.test.ts
index 11dd056..ad05f5c 100644
--- a/packages/game/test/condition.test.ts
+++ b/packages/game/test/condition.test.ts
@@ -4,6 +4,7 @@ import { OutputMatcher } from '../src/condition/OutputMatcher'
 import { PwdMatcher } from '../src/condition/PwdMatcher'
 import { CommandMatcher } from '../src/condition/CommandMatcher'
 import { ErrorMatcher } from '../src/condition/ErrorMatcher.js'
+import { conditionSchema } from '../src/schema'
 
 test('command match', () => {
   const matcher = new CommandMatcher('^echo start$')
@@ -80,3 +81,14 @@ test('condition with NOT', () => {
   expect(condition.match({ command: 'echo start' })).toBe(false)
   expect(condition.match({ command: 'echo hello' })).toBe(true)
 })
+
+it('should parse condition', () => {
+  const condition = {
+    command: 'echo start',
+    output: 'start',
+    not: {
+      pwd: '/home/user',
+    },
+  }
+  expect(conditionSchema.safeParse(condition).error).toBeUndefined()
+})
diff --git a/yarn.lock b/yarn.lock
index 746b92f..13fbb96 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -9747,5 +9747,5 @@ yocto-queue@^0.1.0:
 
 zod@^3.23.8:
   version "3.23.8"
-  resolved "https://registry.npmjs.org/zod/-/zod-3.23.8.tgz"
+  resolved "https://registry.yarnpkg.com/zod/-/zod-3.23.8.tgz#e37b957b5d52079769fb8097099b592f0ef4067d"
   integrity sha512-XBx9AXhXktjUqnepgTiE5flcKIYWi/rme0Eaj+5Y0lftuGBq+jyRu/md4WnuxqgP1ubdpNCsYEYPxrzVHD8d6g==