diff --git a/.eslintrc.js b/.eslintrc.js
index d177747..b323dbd 100644
--- a/.eslintrc.js
+++ b/.eslintrc.js
@@ -60,6 +60,8 @@ module.exports = {
         tsx: 'never',
       },
     ],
+    'no-unused-vars': 'off',
+    '@typescript-eslint/no-unused-vars': 'error',
   },
   overrides: [
     {
diff --git a/packages/game/src/command.ts b/packages/game/src/command.ts
new file mode 100644
index 0000000..6faf783
--- /dev/null
+++ b/packages/game/src/command.ts
@@ -0,0 +1,6 @@
+export interface Command {
+  command: string
+  output: string
+  error: string
+  pwd: string
+}
diff --git a/packages/game/src/condition.ts b/packages/game/src/condition.ts
new file mode 100644
index 0000000..7a050b2
--- /dev/null
+++ b/packages/game/src/condition.ts
@@ -0,0 +1,36 @@
+/* eslint-disable max-classes-per-file */
+import { Command } from './command'
+import { Matcher } from './matcher'
+
+export class PatternMatcher {
+  protected matcher: RegExp | null
+  constructor(pattern?: string, args?: string) {
+    this.matcher = pattern ? new RegExp(pattern, args) : null
+  }
+
+  test(input: string): boolean {
+    if (!this.matcher) {
+      return true
+    }
+    return this.matcher.test(input)
+  }
+}
+
+export class CommandMatcher extends PatternMatcher implements Matcher {
+  match(command: Partial<Command>): boolean {
+    return !!command.command && this.test(command.command)
+  }
+}
+
+export class ErrorMatcher extends PatternMatcher implements Matcher {
+  match(command: Partial<Command>): boolean {
+    if (!this.matcher) {
+      return command.error === ''
+    }
+    return !!command.error && this.test(command.error)
+  }
+}
+
+export class Condition {
+  private matchers: Matcher[] = []
+}
diff --git a/packages/game/src/matcher.ts b/packages/game/src/matcher.ts
new file mode 100644
index 0000000..b1de51d
--- /dev/null
+++ b/packages/game/src/matcher.ts
@@ -0,0 +1,5 @@
+import { Command } from './command'
+
+export interface Matcher {
+  match(command: Partial<Command>): boolean
+}
diff --git a/packages/game/test/condition.test.ts b/packages/game/test/condition.test.ts
new file mode 100644
index 0000000..e6a9f6c
--- /dev/null
+++ b/packages/game/test/condition.test.ts
@@ -0,0 +1,43 @@
+import { test, expect } from '@jest/globals'
+import { PatternMatcher, CommandMatcher, ErrorMatcher } from '../src/condition'
+import { Command } from '../src/command'
+
+test('pattern match', () => {
+  const matcher = new PatternMatcher('^echo start$')
+
+  expect(matcher.test('echo start')).toBe(true)
+  expect(matcher.test('echo start ')).toBe(false)
+})
+
+test('pattern match with flag', () => {
+  const matcher = new PatternMatcher('^echo start$', 'i')
+
+  expect(matcher.test('echo start')).toBe(true)
+  expect(matcher.test('echo Start')).toBe(true)
+  expect(matcher.test('echo Start ')).toBe(false)
+})
+
+test('empty pattern return true', () => {
+  const matcher = new PatternMatcher('')
+  expect(matcher.test('echo start')).toBe(true)
+})
+
+test('empty error return false', () => {
+  const matcher = new ErrorMatcher()
+  expect(matcher.match({ error: '' })).toBe(true)
+  expect(matcher.match({ error: 'permission denied' })).toBe(false)
+})
+
+test('command match', () => {
+  const command: Command = {
+    command: 'echo start',
+    output: 'start',
+    error: '',
+    pwd: '/home/user',
+  }
+
+  const matcher = new CommandMatcher('^echo start$', 'i')
+  expect(matcher.match(command)).toBe(true)
+})
+
+test('condition match', () => {})