diff --git a/packages/models/commandResponder.js b/packages/models/commandResponder.js
new file mode 100644
index 0000000..0078cb7
--- /dev/null
+++ b/packages/models/commandResponder.js
@@ -0,0 +1,19 @@
+import { Schema } from 'mongoose'
+import conditionSchema from './condition.js'
+import responseSchema from './response.js'
+import hintSchema from './hint.js'
+
+const commandResponderSchema = new Schema({
+  condition: {
+    type: conditionSchema,
+    required: false,
+  },
+  responses: {
+    type: [responseSchema],
+    required: true,
+  },
+})
+
+commandResponderSchema.add(hintSchema)
+
+export default commandResponderSchema
diff --git a/packages/models/condition.js b/packages/models/condition.js
new file mode 100644
index 0000000..8f236af
--- /dev/null
+++ b/packages/models/condition.js
@@ -0,0 +1,28 @@
+import { Schema } from 'mongoose'
+
+const fileConditionSchema = new Schema({
+  path: {
+    type: String,
+    required: true,
+  },
+  type: String,
+  exists: {
+    type: Boolean,
+    default: true,
+  },
+})
+
+const conditionSchema = new Schema({
+  command: [String],
+  output: [String],
+  error: [String],
+  pwd: [String],
+  files: [fileConditionSchema],
+})
+
+conditionSchema.add({
+  or: [conditionSchema],
+  not: conditionSchema,
+})
+
+export default conditionSchema
diff --git a/packages/models/exception.js b/packages/models/exception.js
new file mode 100644
index 0000000..60e90b6
--- /dev/null
+++ b/packages/models/exception.js
@@ -0,0 +1,8 @@
+import { Schema } from 'mongoose'
+import commandResponderSchema from './commandResponder.js'
+
+const exceptionSchema = new Schema({})
+
+exceptionSchema.add(commandResponderSchema)
+
+export default exceptionSchema
diff --git a/packages/models/globalException.js b/packages/models/globalException.js
new file mode 100644
index 0000000..5fd191d
--- /dev/null
+++ b/packages/models/globalException.js
@@ -0,0 +1,10 @@
+import { Schema } from 'mongoose'
+import exceptionSchema from './exception.js'
+import requirementSchema from './requirement.js'
+
+const globalExceptionSchema = new Schema({})
+
+globalExceptionSchema.add(exceptionSchema)
+globalExceptionSchema.add(requirementSchema)
+
+export default globalExceptionSchema
diff --git a/packages/models/hint.js b/packages/models/hint.js
new file mode 100644
index 0000000..a46eab9
--- /dev/null
+++ b/packages/models/hint.js
@@ -0,0 +1,10 @@
+import { Schema } from 'mongoose'
+
+const hintSchema = new Schema({
+  hints: {
+    type: [String],
+    required: true,
+  },
+})
+
+export default hintSchema
diff --git a/packages/models/quest.js b/packages/models/quest.js
index 2f808cb..69f4c80 100644
--- a/packages/models/quest.js
+++ b/packages/models/quest.js
@@ -1,98 +1,6 @@
 import { model, Schema } from 'mongoose'
-
-const responseSchema = new Schema({
-  type: {
-    type: String,
-    enum: ['narrative', 'dialogue'],
-    default: 'dialogue',
-    required: true,
-  },
-  content: [String],
-  speaker: { type: String, default: 'Ada' },
-  color: String,
-})
-
-const fileConditionSchema = new Schema({
-  path: {
-    type: String,
-    required: true,
-  },
-  type: String,
-  exists: {
-    type: Boolean,
-    default: true,
-  },
-})
-
-const conditionSchema = new Schema({
-  command: [String],
-  output: [String],
-  error: [String],
-  pwd: [String],
-  files: [fileConditionSchema],
-})
-
-conditionSchema.add({
-  or: [conditionSchema],
-  not: conditionSchema,
-})
-
-const exceptionSchema = new Schema({
-  condition: {
-    type: conditionSchema,
-    required: false,
-  },
-  catchAll: {
-    type: Boolean,
-    required: true,
-    default: false,
-  },
-  responses: {
-    type: [responseSchema],
-    required: true,
-  },
-  hints: {
-    type: [String],
-    required: true,
-  },
-})
-
-const stageSchema = new Schema({
-  id: {
-    type: String,
-    required: true,
-  },
-  task: {
-    type: String,
-  },
-  requirements: [
-    {
-      type: String,
-      required: true,
-    },
-  ],
-  repeatable: {
-    type: Boolean,
-    required: true,
-    default: false,
-  },
-  condition: {
-    type: conditionSchema,
-    required: true,
-  },
-  responses: {
-    type: [responseSchema],
-    required: true,
-  },
-  hints: {
-    type: [String],
-    required: true,
-  },
-  exceptions: {
-    type: [exceptionSchema],
-    required: true,
-  },
-})
+import stageSchema from './stage.js'
+import globalExceptionSchema from './globalException.js'
 
 const Quest = model(
   'Quest',
@@ -126,6 +34,10 @@ const Quest = model(
       type: [stageSchema],
       required: true,
     },
+    exceptions: {
+      type: [globalExceptionSchema],
+      required: true,
+    },
   })
 )
 
diff --git a/packages/models/requirement.js b/packages/models/requirement.js
new file mode 100644
index 0000000..9edf61e
--- /dev/null
+++ b/packages/models/requirement.js
@@ -0,0 +1,12 @@
+import { Schema } from 'mongoose'
+
+const requirementSchema = new Schema({
+  requirements: [
+    {
+      type: String,
+      required: true,
+    },
+  ],
+})
+
+export default requirementSchema
diff --git a/packages/models/response.js b/packages/models/response.js
new file mode 100644
index 0000000..a2bf5b0
--- /dev/null
+++ b/packages/models/response.js
@@ -0,0 +1,15 @@
+import { Schema } from 'mongoose'
+
+const responseSchema = new Schema({
+  type: {
+    type: String,
+    enum: ['narrative', 'dialogue'],
+    default: 'dialogue',
+    required: true,
+  },
+  content: [String],
+  speaker: { type: String, default: 'Ada' },
+  color: String,
+})
+
+export default responseSchema
diff --git a/packages/models/stage.js b/packages/models/stage.js
new file mode 100644
index 0000000..73c6070
--- /dev/null
+++ b/packages/models/stage.js
@@ -0,0 +1,24 @@
+import { Schema } from 'mongoose'
+import commandResponderSchema from './commandResponder.js'
+import stageExceptionSchema from './stageException.js'
+import requirementSchema from './requirement.js'
+
+const stageSchema = new Schema({
+  id: {
+    type: String,
+    required: true,
+  },
+  task: {
+    type: String,
+    required: true,
+  },
+  exceptions: {
+    type: [stageExceptionSchema],
+    required: true,
+  },
+})
+
+stageSchema.add(commandResponderSchema)
+stageSchema.add(requirementSchema)
+
+export default stageSchema
diff --git a/packages/models/stageException.js b/packages/models/stageException.js
new file mode 100644
index 0000000..f11d7d7
--- /dev/null
+++ b/packages/models/stageException.js
@@ -0,0 +1,14 @@
+import { Schema } from 'mongoose'
+import exceptionSchema from './exception.js'
+
+const stageExceptionSchema = new Schema({
+  catchAll: {
+    type: Boolean,
+    required: true,
+    default: false,
+  },
+})
+
+stageExceptionSchema.add(exceptionSchema)
+
+export default stageExceptionSchema
diff --git a/quests/cast/game.yml b/quests/cast/game.yml
index 4c6f229..3482ee4 100644
--- a/quests/cast/game.yml
+++ b/quests/cast/game.yml
@@ -9,14 +9,6 @@ requirements:
   - get-started
 
 stages:
-  - id: warning-01
-    repeatable: true
-    condition:
-      command:
-        - '　'
-    hints:
-      - '!! 請勿使用全形空格 !!'
-
   - id: start
     task: 輸入 `echo start` 來開始教程
     condition:
@@ -73,3 +65,11 @@ stages:
           - 你成功的在終端機上顯示了 `How are you?`。
           - 相信你已經了解如何使用 `echo` 指令來顯示文字了。
           - 之後如果要在終端機顯示文字，記得可以使用 `echo` 指令。
+
+exceptions:
+  - repeatable: true
+    condition:
+      command:
+        - '　'
+    hints:
+      - '!! 請勿使用全形空格 !!'
diff --git a/quests/copy/game.yml b/quests/copy/game.yml
index d48d0e8..15eda11 100644
--- a/quests/copy/game.yml
+++ b/quests/copy/game.yml
@@ -9,14 +9,6 @@ requirements:
   - create
 
 stages:
-  - id: warning-01
-    repeatable: true
-    condition:
-      command:
-        - '　'
-    hints:
-      - '!! 請勿使用全形空格 !!'
-
   - id: start
     task: 輸入 `echo start` 來開始
     condition:
diff --git a/quests/create/game.yml b/quests/create/game.yml
index 41bcb13..647b41e 100644
--- a/quests/create/game.yml
+++ b/quests/create/game.yml
@@ -10,14 +10,6 @@ requirements:
   - read
 
 stages:
-  - id: warning-01
-    repeatable: true
-    condition:
-      command:
-        - '　'
-    hints:
-      - '!! 請勿使用全形空格 !!'
-
   - id: start
     task: 輸入 `echo start` 來開始
     condition:
@@ -68,6 +60,7 @@ stages:
       - ➤  輸入 `cat hello.txt` 來查看 `hello.txt` 檔案的內容
 
   - id: cat
+    task: 使用 `cat` 指令來查看 `hello.txt` 檔案的內容
     condition:
       command:
         - ^cat hello.txt$
diff --git a/quests/exceptions.yml b/quests/exceptions.yml
new file mode 100644
index 0000000..6ffe5f5
--- /dev/null
+++ b/quests/exceptions.yml
@@ -0,0 +1,6 @@
+exceptions:
+  - condition:
+      command:
+        - '`'
+    hints:
+      - '!! 不需要輸入上下引號 !!'
diff --git a/quests/explore/game.yml b/quests/explore/game.yml
index 707c39b..5aa292e 100644
--- a/quests/explore/game.yml
+++ b/quests/explore/game.yml
@@ -10,14 +10,6 @@ requirements:
   - get-started
 
 stages:
-  - id: warning-01
-    repeatable: true
-    condition:
-      command:
-        - '　'
-    hints:
-      - '!! 請勿使用全形空格 !!'
-
   - id: start
     task: 輸入 `echo start` 來開始教程
     condition:
@@ -115,7 +107,7 @@ stages:
       pwd:
         - ^/home/commander/folder1$
       command:
-        - ls
+        - ^ls$
     responses:
       - content:
           - 你現在可以看到 `folder1` 資料夾中有兩的檔案，分別是 `file1.txt` 跟 `file2.txt`。
diff --git a/quests/get-started/game.yml b/quests/get-started/game.yml
index 3d09d66..9fd00fb 100644
--- a/quests/get-started/game.yml
+++ b/quests/get-started/game.yml
@@ -9,22 +9,6 @@ instruction: |
   請你在終端機中的 `commander:~ $` 後面輸入 `echo start` 並按下 Enter 來開始教程。
 
 stages:
-  - id: warning-01
-    repeatable: true
-    condition:
-      command:
-        - '　'
-    hints:
-      - '!! 請勿使用全形空格 !!'
-
-  - id: warning-02
-    repeatable: true
-    condition:
-      command:
-        - '`'
-    hints:
-      - '!! 不需要輸入上下引號 !!'
-
   - id: start
     task: 輸入 `echo start` 來開始教程
     condition:
diff --git a/quests/move/game.yml b/quests/move/game.yml
index f694ae6..413bc35 100644
--- a/quests/move/game.yml
+++ b/quests/move/game.yml
@@ -9,14 +9,6 @@ requirements:
   - create
 
 stages:
-  - id: warning-01
-    repeatable: true
-    condition:
-      command:
-        - '　'
-    hints:
-      - '!! 請勿使用全形空格 !!'
-
   - id: start
     task: 輸入 `echo start` 來開始
     condition:
diff --git a/quests/path/game.yml b/quests/path/game.yml
index 0aedf6c..dca6f75 100644
--- a/quests/path/game.yml
+++ b/quests/path/game.yml
@@ -11,14 +11,6 @@ requirements:
   - explore
 
 stages:
-  - id: warning-01
-    repeatable: true
-    condition:
-      command:
-        - '　'
-    hints:
-      - '!! 請勿使用全形空格 !!'
-
   - id: start
     task: 輸入 `echo start` 來開始教程
     condition:
diff --git a/quests/read/game.yml b/quests/read/game.yml
index ad317bc..6407d17 100644
--- a/quests/read/game.yml
+++ b/quests/read/game.yml
@@ -9,14 +9,6 @@ requirements:
   - path
 
 stages:
-  - id: warning-01
-    repeatable: true
-    condition:
-      command:
-        - '　'
-    hints:
-      - '!! 請勿使用全形空格 !!'
-
   - id: start
     task: 輸入 `echo start` 來開始教程
     condition:
diff --git a/quests/remove/game.yml b/quests/remove/game.yml
index 4560ba3..d6532fc 100644
--- a/quests/remove/game.yml
+++ b/quests/remove/game.yml
@@ -13,14 +13,6 @@ requirements:
   - move
 
 stages:
-  - id: warning-01
-    repeatable: true
-    condition:
-      command:
-        - '　'
-    hints:
-      - '!! 請勿使用全形空格 !!'
-
   - id: start
     task: 輸入 `echo start` 來開始
     condition:
diff --git a/server/src/game/commandHandler.js b/server/src/game/commandHandler.js
index f45a839..4b271ff 100644
--- a/server/src/game/commandHandler.js
+++ b/server/src/game/commandHandler.js
@@ -56,7 +56,7 @@ export default class CommandHandler extends SessionHandler {
       this.session.graph = graph
     } catch (e) {
       logger.error('Update file graph failed', {
-        error: e,
+        error: e.message,
         session: this.session.id,
         graph: this.session.graph,
         discover: this.params.discover,
@@ -122,9 +122,9 @@ export default class CommandHandler extends SessionHandler {
   async run() {
     try {
       this.quest = await Quest.findById(this.session.quest)
-      const stages = this.getStages()
+      const stages = this.getUnlockedComponents(this.quest.stages)
       if (stages.length === 0) {
-        logger.warn('stage not found', this.session.tasks)
+        logger.warn('stage not found', { session: this.session.id })
         return {}
       }
 
@@ -136,27 +136,44 @@ export default class CommandHandler extends SessionHandler {
       )
 
       const stage = stages.find((_, i) => matches[i])
-      if (!stage) {
-        for (const s of stages) {
+      if (stage) {
+        const response = this.execute(stage)
+
+        return {
+          stage: stage.id,
+          end: this.session.status === 'finished',
+          ...response,
+        }
+      }
+
+      // stage exception
+      for (const s of stages) {
+        // eslint-disable-next-line no-await-in-loop
+        const exception = await this.checkException(s)
+        if (exception) {
+          return this.executeException(exception)
+        }
+      }
+
+      // global exception
+      if (this.quest.exceptions.length > 0) {
+        const globalExceptions = this.getUnlockedComponents(
+          this.quest.exceptions
+        )
+        for (const exception of globalExceptions) {
           // eslint-disable-next-line no-await-in-loop
-          const exception = await this.checkException(s)
-          if (exception) {
+          if (await this.isMatch(exception.condition)) {
             return this.executeException(exception)
           }
         }
-        return {}
       }
-      const response = this.execute(stage)
 
-      return {
-        stage: stage.id,
-        end: this.session.status === 'finished',
-        ...response,
-      }
+      return {}
     } catch (err) {
       logger.error('CommandHandler error', {
-        error: err,
-        session: this.session.id,
+        error: err.message,
+        session: this.session._id,
+        quest: this.quest._id,
         command: this.commandInput,
       })
       return {}
diff --git a/server/src/game/sessionHandler.js b/server/src/game/sessionHandler.js
index 2312c4c..a9b89f0 100644
--- a/server/src/game/sessionHandler.js
+++ b/server/src/game/sessionHandler.js
@@ -19,16 +19,14 @@ export default class SessionHandler {
     return task ? task.completed : false
   }
 
-  getStages() {
-    return this.quest.stages.filter(
-      (stage) =>
-        stage.requirements.every((r) => this.isCompleted({ id: r })) &&
-        (stage.repeatable || !this.isCompleted(stage))
+  getUnlockedComponents(components) {
+    return components.filter((component) =>
+      component.requirements.every((r) => this.isCompleted({ id: r }))
     )
   }
 
   getNewTasks() {
-    const stages = this.getStages()
+    const stages = this.getUnlockedComponents(this.quest.stages)
     return stages
       .filter((s) => s.task)
       .filter((s) => !this.session.tasks.some((t) => t.id === s.id))
diff --git a/server/src/index.js b/server/src/index.js
index 0004af7..67c102f 100644
--- a/server/src/index.js
+++ b/server/src/index.js
@@ -38,7 +38,12 @@ async function main() {
     await setupTest()
   }
 
-  await loadAndUpdateQuests()
+  try {
+    await loadAndUpdateQuests()
+  } catch (err) {
+    logger.error('Failed to load quests', err)
+    return
+  }
   expiryRemovalScheduler()
 
   const file = await fs.readFile('./swagger.yaml', 'utf8')
diff --git a/server/src/utils/logger.js b/server/src/utils/logger.js
index a540c27..2eaf76e 100644
--- a/server/src/utils/logger.js
+++ b/server/src/utils/logger.js
@@ -1,9 +1,13 @@
-import winston from 'winston'
+import winston, { format } from 'winston'
 import config from '../config.js'
 
 const logger = winston.createLogger({
   level: 'info',
-  format: winston.format.json(),
+  format: format.combine(
+    format.errors({ stack: true }),
+    format.timestamp(),
+    format.json()
+  ),
   defaultMeta: { service: 'backend', timestamp: new Date().toISOString() },
   transports: [
     //
diff --git a/server/src/utils/quest.js b/server/src/utils/quest.js
index 056769e..dc96f73 100644
--- a/server/src/utils/quest.js
+++ b/server/src/utils/quest.js
@@ -7,6 +7,15 @@ import logger from './logger.js'
 
 const questDirectory = path.join(process.cwd(), '..', 'quests')
 
+class QuestValidationError extends Error {
+  constructor(message, questId, error) {
+    super(message)
+    this.name = 'QuestValidationError'
+    this.questId = questId
+    this.error = error
+  }
+}
+
 async function mapQuests(callback) {
   const questNames = await fs.readdir(questDirectory, {
     withFileTypes: true,
@@ -23,12 +32,20 @@ async function mapQuests(callback) {
   )
 }
 
+async function loadGlobalExceptions() {
+  const exceptionsPath = path.join(questDirectory, 'exceptions.yml')
+  const body = await fs.readFile(exceptionsPath, 'utf-8')
+  return yaml.parse(body)
+}
+
 export async function loadAndUpdateQuests() {
   await Quest.deleteMany({})
+  const { exceptions } = await loadGlobalExceptions()
+  console.log(exceptions)
   return mapQuests(async (id, questPath) => {
     const files = await fs.readdir(questPath)
     if (!files.includes('game.yml')) {
-      throw new Error(`Quest ${id} is missing game.yml`)
+      throw new QuestValidationError(`Missing game.yml`, id)
     }
 
     try {
@@ -44,10 +61,12 @@ export async function loadAndUpdateQuests() {
         image,
         ...questData,
       })
+      quest.exceptions.push(...exceptions)
       await quest.save()
     } catch (error) {
-      logger.error(`Error parsing quest ${id}:`, error)
-      throw error
+      console.error(error)
+      logger.error(`Error parsing quest`, { id, error })
+      throw new QuestValidationError(`Error parsing quest`, id, error)
     }
   })
 }