唤醒勇虎 是钢铁雄心4的第一个成熟的扩展包。 它于2017年11月15日宣布，并于2018年3月8日发布，与1.5版本更新同步发售。
自1.14.3版本（2024-3-21）起，唤醒勇虎扩展包被整合进了基础游戏，不再作为单独分销品来提供。[1]
扩展功能
- 中国新国策树:在你对未来的憧憬指引下领导中共或中华民国赢得战争。
- 修改了德国和日本的国策树:两个轴心国现在有了不同的历史走向，包括推翻希特勒或在日本建立共产主义或民主。
- 将军特质和能力:将军的特质现在可以解锁强大的指挥能力，允许极大的灵活性和创造力。
- 决策和任务:历史决策和国家任务为政治点数的使用提供了新的场所，从国内政治开始的特殊项目。
- 增加了发送志愿军到其他国家的能力，让你看到他们的军队，以及基于国家军事经验，和接收国少量的组织和计划速度。
- 更多:从战场上缴获装备，使用志愿航空队，以及新的音乐和美术。
- 增加了一种中国军阀独有的新货币:政治支持点。作为军阀积累足够的政治支持点来夺取控制中国的命运。
Free features
- 主条目：Patch 1.5
- 新的 “稳定度 ”和 “战争支持度 ”机制取代了 “凝聚度 ”机制，以更好地模拟您的国家的状态，以及与之相适应的许多决策和更改。
- 日本的新国策树
- 全面修改并扩展了德国的国策树：为工业、航空、海军和法西斯道路添加了新国策，并改进了某些现有国策。
- 增加了指挥链 * 现在可以让元帅指挥将军率领的军队，以获得两者的奖励
- 将军现在有 4 种技能值：攻击、防御、计划、后勤，而不是单一技能。
- 指挥官晋升时不再丢失特质
- 指挥官可以（而且通常会）从新的个性特征开始
- 添加了 “决策”，它是国策和事件之间的中间地带，允许大量的可修改性和机制
- 添加了许多决策，以配合新的决策机制。
- 添加了 “适应 ”核心机制，让部队适应恶劣气候
- 现在可以使用 “额外地面部队 ”能力，将部分指挥力量用于提高区域内的空中效率
- 添加了 “踢出派系 ”外交行动(for SPAAAAARTA!!! /Podcat am I 2011 meme:ing again?)
- 新的历史模板列表。增强了与 AI 会面时的沉浸感，让玩家控制事情如何命名的权力大大增加。
- 新的撤退机制。我们现在将撤退和强制撤退区分开来，这意味着你在命令部队撤退时不会被压制，而且撤退将减少许多微操
- 用于查看损失和击沉船只的新界面
- 大规模改进生产界面，增加了过滤器、折叠、拖放功能，并允许将 15 家以上的工厂分配到一条生产线上。
- 新的战争总览，具有派别、过滤器和排序功能。此外，我们还推荐使用汇总战争概述。现在的战争更加流畅，可以处理三方战争，避免了过去战争合并等问题。
- 几种新的炼油技术允许您控制橡胶和石油的产出量。
- 基础设施现在会影响资源的开采量。建设一个区域可以解锁更多资源，轰炸则会降低资源产出。
- 特种部队现在受限于军队的百分比或最低营数
- 几项新技术可为特种部队提供奖励或控制数量与质量
- 现在可以为军队附加航空翼，航空翼将跟随军队执行任务
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 |