喚醒勇虎 是鋼鐵雄心4的第一個成熟的擴展包。 它於2017年11月15日宣布，並於2018年3月8日發布，與1.5版本更新同步發售。
1.14.3版本（2024-3-21）後，喚醒勇虎擴展包已整合進了基礎遊戲，不需要單獨購買。[1]
擴展功能
- 中國地區的新國策樹：領導
中共或File:China.png 中華民國贏得抗日戰爭。 - 修改了
德意志國和File:Japan.png 日本的國策樹：兩個法西斯國家現在可以走上不同的歷史道路，如推翻希特勒的統治和建立日本的共產或民主政體。 - 將軍特質和能力：將領的特質現在可以解鎖強大的指揮能力，從而帶來極大的靈活和創造力。
- 決議和任務：歷史決策和國家任務為政治點數的使用提供了新的地方，如操控國內政治和啟動特殊項目。
- 增加了派送志願軍到其他國家的能力，讓你能看到交戰國的軍隊，並為我方提供三軍經驗。接收國也可以獲得少量的組織度和計劃速度。
- 增加了一種中國軍閥獨有的新貨幣：政治支持點。作為軍閥積累足夠的政治支持點來奪取控制中國的命運。
- 更多：從戰場上繳獲裝備、使用志願航空隊和新的音樂和美術。
Free features
- 主條目：Patch 1.5
- 新的 「穩定度 」和 「戰爭支持度 」機製取代了 「凝聚度 」機制，以更好地模擬您的國家的狀態，以及與之相適應的許多決策和更改。
- 日本的新國策樹
- 全面修改並擴展了德國的國策樹：為工業、航空、海軍和法西斯道路添加了新國策，並改進了某些現有國策。
- 增加了指揮鏈 * 現在可以讓元帥指揮將軍率領的軍隊，以獲得兩者的獎勵
- 將軍現在有 4 種技能值：攻擊、防禦、計劃、後勤，而不是單一技能。
- 指揮官晉升時不再丟失特質
- 指揮官可以（而且通常會）從新的個性特徵開始
- 添加了 「決策」，它是國策和事件之間的中間地帶，允許大量的可修改性和機制
- 添加了許多決策，以配合新的決策機制。
- 添加了 「適應 」核心機制，讓部隊適應惡劣氣候
- 現在可以使用 「額外地面部隊 」能力，將部分指揮力量用於提高區域內的空中效率
- 添加了 「踢出派系 」外交行動(for SPAAAAARTA!!! /Podcat am I 2011 meme:ing again?)
- 新的歷史模板列表。增強了與 AI 會面時的沉浸感，讓玩家控制事情如何命名的權力大大增加。
- 新的撤退機制。我們現在將撤退和強制撤退區分開來，這意味着你在命令部隊撤退時不會被壓制，而且撤退將減少許多微操
- 用於查看損失和擊沉船隻的新界面
- 大規模改進生產界面，增加了過濾器、摺疊、拖放功能，並允許將 15 家以上的工廠分配到一條生產線上。
- 新的戰爭總覽，具有派別、過濾器和排序功能。此外，我們還推薦使用匯總戰爭概述。現在的戰爭更加流暢，可以處理三方戰爭，避免了過去戰爭合併等問題。
- 幾種新的煉油技術允許您控制橡膠和石油的產出量。
- 基礎設施現在會影響資源的開採量。建設一個區域可以解鎖更多資源，轟炸則會降低資源產出。
- 特種部隊現在受限於軍隊的百分比或最低營數
- 幾項新技術可為特種部隊提供獎勵或控制數量與質量
- 現在可以為軍隊附加航空翼，航空翼將跟隨軍隊執行任務
Developer diaries
All developer diaries about the Waking the Tiger expansion and patch 1.5 (aka Cornflakes).
| No. | Title and Link | Description | Date |
|---|---|---|---|
| 1 | Future and Cornflakes | Podcat shares the team's (non-exhaustive) list of features to act as a future development roadmap for HoI4 | 2017-08-23 |
| 2 | Our development process | Sofia "KimchiViking" Höglund, HoI4's project lead, explains the development cycle, from design to implementation. | 2017-08-30 |
| 3 | A Product Manager's Role | "Firebolt", HoI4's product manager, on the intricacies of budgeting a game development. | 2017-09-06 |
| 4 | Chain of Command | Podcat on spicing things up in the HoI4 chain of command as part of patch 1.5 | 2017-09-13 |
| 5 | Stability and War Support | Stability and War support to replace National unity in the next patch | 2017-09-20 |
| 6 | Division Namelists | Pallidum, HoI4's game designer, inserting some flavor (and logic) to division names. | 2017-09-27 |
| 7 | Synthetic Dawn | Refinements to synthetic refineries and inter-linking infrastructure with resources | 2017-10-04 |
| 8 | Bag of Tricks #1 | Smaller improvements to the game: control groups, divisions consolidation, removal from faction, mini-map & pinging. | 2017-10-11 |
| 9 | A New Germany | Revised focus tree for Germany as part of requested alternate history options | 2017-10-18 |
| 10 | Bag of Tricks #2 | Another small features and improvements, this time with relation to equipment | 2017-10-25 |
| 11 | Airplanes and Lootboxes | Further improvement of air related aspects | 2017-11-01 |
| 12 | Decisive Action | Adding decisions, missions, crises and special projects to the game | 2017-11-08 |
| 13 | Nationalist China | The 1st focus tree for China (the nationalist path) as well as the announcement of Waking the Tiger expansion. | 2017-11-15 |
| 14 | Communist China | The 2nd focus tree for China (the communist path) along with an example of the new decision system in action. | 2017-11-22 |
| 15 | Leaders, abilities and Traits | Revamped and expanded trait system and the mysterious "red phone" icon (aka command power). | 2017-11-29 |
| 16 | Acclimatization and Special Forces | Troops are now affected by hot and cold climates, and new changes to special forces. | 2017-12-06 |
| 17 | Border Wars: The Last Warlord | More detail on the Chinese warlords. | 2017-12-13 |
| 18 | Christmas & Modding | Modding guide for the new decisions & missions system in patch 1.5. | 2017-12-20 |
| 19 | New German Divisional Namelist | Further improvement of incoming German unit namelist. | 2017-12-27 |
| 20 | Japan rework | A rework of the Japanese national focus tree. | 2018-01-03 |
| 21 | Bag of Tricks #3 | 3rd assortment of small improvements: attachés, extra ground crews, historical army insignias, and volunteer air wings. | 2018-01-10 |
| 22 | Manchukuo | The last unrevealed focus tree for Waking the Tiger: "Manchukuo". | 2018-01-17 |
| 23 | War Changes and game Difficulty | Changes to 3-way war handling and addition of 2 more difficulty settings. | 2018-01-24 |
| 24 | Sound, Music and Art for Tiger | On the topic of the artistic additions to Waking the Tiger. | 2018-01-31 |
| 25 | Naval Updates | Improvements of naval matters: losses and kills overview, convoys raiding, transports interception, and more. | 2018-02-07 |
| 26 | Formable Nations and Achievements | New goals to strive for: formable nations and some 18 achievements. | 2018-02-14 |
| 27 | Performance and AI | Performance and AI. | 2018-02-21 |
| 28 | Recap Episode | What is coming in Waking the Tiger and the 1.5 Cornflakes. | 2018-02-28 |
| 29 | Pre-Release and International Women's Day | Women's contribution during the second world war. | 2018-03-07 |
| 30 | Post-Release patch | Info about patch 1.5.1 | 2018-03-14 |
| 31 | 1.5.2 Update #1 | Info about patch 1.5.2: German border changes, commander XP gain changes, multiplayer desyncs, and more. | 2018-03-21 |
| 32 | 1.5.2 Update #2 and Modding Goodies | Info about patch 1.5.2: Air Balance and Changes, Nukes and Surrender, Manchukuo, Modding and more. | 2018-03-28 |
| 33 | 1.5.2 Update #3 and Telemetry | An updated beta and multiplayer telemetry | 2018-04-04 |
| 34 | 1.5.2, Future Roadmap and Ironclad | The return of the bullet list and possible future development roadmap | 2018-04-11 |