diff --git a/docs/architecture/rewrite-plan.md b/docs/architecture/rewrite-plan.md
index 1570891..279f161 100644
--- a/docs/architecture/rewrite-plan.md
+++ b/docs/architecture/rewrite-plan.md
@@ -5,7 +5,7 @@ Vue 3 frontends.
 
 ## Planned Layout
 
-- `/packages/common`: shared utilities and type definitions (no infra)
+- `/packages/common`: shared utilities and type definitions (RNG/bytes/테스트 RNG 포함, no infra)
 - `/packages/infra`: Prisma/Redis connectors and other runtime infra
 - `/packages/logic`: pure game logic with DI and interfaces
 - `/app/gateway-frontend`: gateway UI
diff --git a/packages/common/package.json b/packages/common/package.json
index 9c17ebd..c3f65ec 100644
--- a/packages/common/package.json
+++ b/packages/common/package.json
@@ -11,6 +11,8 @@
         "lint": "node -e \"console.log('lint not configured')\"",
         "test": "node -e \"console.log('test not configured')\""
     },
-    "dependencies": {},
+    "dependencies": {
+        "js-sha512": "^0.9.0"
+    },
     "devDependencies": {}
 }
diff --git a/packages/common/src/index.ts b/packages/common/src/index.ts
index cb0ff5c..4b4a672 100644
--- a/packages/common/src/index.ts
+++ b/packages/common/src/index.ts
@@ -1 +1,8 @@
-export {};
+export * from './rng.js';
+export * from './util/BytesLike.js';
+export * from './util/convertBytesLikeToArrayBuffer.js';
+export * from './util/convertBytesLikeToUint8Array.js';
+export * from './util/LiteHashDRBG.js';
+export * from './util/RNG.js';
+export * from './util/RandUtil.js';
+export * from './util/TestRNG.js';
diff --git a/packages/logic/src/ports/rng.ts b/packages/common/src/rng.ts
similarity index 100%
rename from packages/logic/src/ports/rng.ts
rename to packages/common/src/rng.ts
diff --git a/packages/logic/src/util/BytesLike.ts b/packages/common/src/util/BytesLike.ts
similarity index 100%
rename from packages/logic/src/util/BytesLike.ts
rename to packages/common/src/util/BytesLike.ts
diff --git a/packages/logic/src/util/LiteHashDRBG.ts b/packages/common/src/util/LiteHashDRBG.ts
similarity index 100%
rename from packages/logic/src/util/LiteHashDRBG.ts
rename to packages/common/src/util/LiteHashDRBG.ts
diff --git a/packages/logic/src/util/RNG.ts b/packages/common/src/util/RNG.ts
similarity index 100%
rename from packages/logic/src/util/RNG.ts
rename to packages/common/src/util/RNG.ts
diff --git a/packages/logic/src/util/RandUtil.ts b/packages/common/src/util/RandUtil.ts
similarity index 100%
rename from packages/logic/src/util/RandUtil.ts
rename to packages/common/src/util/RandUtil.ts
diff --git a/packages/logic/src/util/TestRNG.ts b/packages/common/src/util/TestRNG.ts
similarity index 100%
rename from packages/logic/src/util/TestRNG.ts
rename to packages/common/src/util/TestRNG.ts
diff --git a/packages/logic/src/util/convertBytesLikeToArrayBuffer.ts b/packages/common/src/util/convertBytesLikeToArrayBuffer.ts
similarity index 100%
rename from packages/logic/src/util/convertBytesLikeToArrayBuffer.ts
rename to packages/common/src/util/convertBytesLikeToArrayBuffer.ts
diff --git a/packages/logic/src/util/convertBytesLikeToUint8Array.ts b/packages/common/src/util/convertBytesLikeToUint8Array.ts
similarity index 100%
rename from packages/logic/src/util/convertBytesLikeToUint8Array.ts
rename to packages/common/src/util/convertBytesLikeToUint8Array.ts
diff --git a/packages/logic/package.json b/packages/logic/package.json
index c338457..af8cc4f 100644
--- a/packages/logic/package.json
+++ b/packages/logic/package.json
@@ -18,7 +18,7 @@
         "test": "vitest run --config vitest.config.ts"
     },
     "dependencies": {
-        "js-sha512": "^0.9.0"
+        "@sammo-ts/common": "workspace:*"
     },
     "devDependencies": {
         "vitest": "^4.0.16"
diff --git a/packages/logic/src/index.ts b/packages/logic/src/index.ts
index f665292..bcb5d0e 100644
--- a/packages/logic/src/index.ts
+++ b/packages/logic/src/index.ts
@@ -1,11 +1,4 @@
 export * from './domain/entities.js';
-export * from './ports/rng.js';
+export type { RandomGenerator } from '@sammo-ts/common';
 export * from './ports/world.js';
 export * from './triggers/index.js';
-export * from './util/BytesLike.js';
-export * from './util/convertBytesLikeToArrayBuffer.js';
-export * from './util/convertBytesLikeToUint8Array.js';
-export * from './util/LiteHashDRBG.js';
-export * from './util/RNG.js';
-export * from './util/RandUtil.js';
-export * from './util/TestRNG.js';
diff --git a/packages/logic/src/triggers/general.ts b/packages/logic/src/triggers/general.ts
index 32704b9..16848e3 100644
--- a/packages/logic/src/triggers/general.ts
+++ b/packages/logic/src/triggers/general.ts
@@ -1,5 +1,5 @@
 import type { General, GeneralTriggerState } from '../domain/entities.js';
-import type { RandomGenerator } from '../ports/rng.js';
+import type { RandomGenerator } from '@sammo-ts/common';
 import type { WorldStateRepository } from '../ports/world.js';
 import { TriggerCaller, type Trigger } from './core.js';
 
diff --git a/packages/logic/test/rng.test.ts b/packages/logic/test/rng.test.ts
index 45e8238..a83df09 100644
--- a/packages/logic/test/rng.test.ts
+++ b/packages/logic/test/rng.test.ts
@@ -1,8 +1,11 @@
 import { describe, expect, it } from 'vitest';
-import { bufferByteSize, LiteHashDRBG } from '../src/util/LiteHashDRBG.js';
-import { RandUtil } from '../src/util/RandUtil.js';
-import { convertBytesLikeToArrayBuffer } from '../src/util/convertBytesLikeToArrayBuffer.js';
-import { convertBytesLikeToUint8Array as toBytes } from '../src/util/convertBytesLikeToUint8Array.js';
+import {
+    bufferByteSize,
+    convertBytesLikeToArrayBuffer,
+    convertBytesLikeToUint8Array as toBytes,
+    LiteHashDRBG,
+    RandUtil,
+} from '@sammo-ts/common';
 
 type Bytes = ArrayBuffer | DataView<ArrayBuffer> | Uint8Array<ArrayBuffer>;
 type MaybeBytes = Bytes | string;
diff --git a/packages/logic/test/test-rngs.test.ts b/packages/logic/test/test-rngs.test.ts
index b4143de..b0c8801 100644
--- a/packages/logic/test/test-rngs.test.ts
+++ b/packages/logic/test/test-rngs.test.ts
@@ -1,5 +1,5 @@
 import { describe, expect, it } from 'vitest';
-import { ConstantRNG, MidpointRNG, SequenceRNG, SineRNG } from '../src/util/TestRNG.js';
+import { ConstantRNG, MidpointRNG, SequenceRNG, SineRNG } from '@sammo-ts/common';
 
 const toArray = (bytes: Uint8Array): number[] => Array.from(bytes);
 
diff --git a/packages/logic/vitest.config.ts b/packages/logic/vitest.config.ts
index 97cb2e9..69a4a8a 100644
--- a/packages/logic/vitest.config.ts
+++ b/packages/logic/vitest.config.ts
@@ -1,6 +1,13 @@
+import path from 'node:path';
+
 import { defineConfig } from 'vitest/config';
 
 export default defineConfig({
+    resolve: {
+        alias: {
+            '@sammo-ts/common': path.resolve(__dirname, '../common/src/index.ts'),
+        },
+    },
     test: {
         environment: 'node',
         globals: true,