In a post last year I showed an early version of the tech tree and explained why I’ve renamed scientists to “engineers” and tech to “research” in Rebuild 3. Since then I’ve changed how a few research projects work, added Preemptive Strikes and replaced Fort Policies with Survivor Management. Here’s how the research tree looks in its final form:
Zombies track:
Start on the left tree to kill zed more efficiently and reduce danger on missions.
| Level | Research | What does it do? |
| 1 | Zombie Vitals | 10% more efficient zombie killing – speeds up zombie killing missions |
| 2 | Basic Traps | Craftable zombie killing building upgrade – kills 5 unmassed zed per day |
| 2 | Zombie Avoidance | 25% less danger from mission distance |
| 3 | Disease Vectors | Reduced chance of zombie bites – during random events |
| 3 | Anti-Zombie Armor | 25% better zombie defense – lowers danger rates |
| 4 | Zombie Bait | Draw in zed to a building – craftable from food, distracts mobs and roamers |
| 5 | Advanced Traps | Better craftable zed traps – kills 10 unmassed zed per day |
| 5 | Fort Silence | Fewer hidden zombies spawn beside the fort |
| 7 | Improved Defense | Increase building defense by 1% per level, repeat |
Buildings track:
Start on the center tree for more options in your fort buildings.
| Level | Research | What does it do? |
| 1 | Construction | Build bars, schools, churches, labs, etc |
| 2 | Watch Towers | Defensive building upgrade – +5 defense to upgraded building and +2.5 to neighboring buildings |
| 2 | Generator Power | 10% faster workshop crafting – this research is automatically granted if you repair a power plant |
| 3 | Bunker Towers | Defensive building upgrade – +10 defense to upgraded building and +5 to neighboring buildings |
| 3 | Fertilizer | Extra food from farms – also increases max food storage |
| 4 | Improved Walls | Better fort-wide defense – +1 to all buildings |
| 4 | Irrigation | Prevent drought – also increases max food storage |
| 5 | Advanced Construction | Build and fortify 25% faster |
| 6 | Turret Towers | Defensive building upgrade – +15 defense to upgraded building and +15 to neighboring buildings |
| 6 | Electrified Walls | Improved fort-wide defense – +1 to all buildings cumulative with Improved Walls |
| 6 | Pesticides | Prevent pests, extra food on farming missions – also increases max food storage |
| 7 | Improved Farms | 1% bonus to food production per level, repeat |
Survivor track:
Start on the rightmost tree for management skills that make your survivors stronger.
| Level | Research | What does it do? |
| 1 | Survivor Management | See happiness, relationships, and talk to survivors – allows awarding level perks |
| 2 | Signposts | Attract survivors – in random events |
| 2 | Improved Teaching | 50% more skill from training |
| 3 | Paramedic Training | 10% better chance of injury instead of death – for all survivors |
| 3 | Improved Scouting | Reveal further when scouting – reveals adjacent buildings |
| 4 | Searchlights | Attract more survivors – in random events |
| 4 | Medkits & Medicine | Craftable medicine in workshops – use medkits to instantly heal injuries |
| 5 | Fireworks | Craftable entertainment – use to improve happiness |
| 5 | Doctor Training | Extra 10% chance of injury instead of death – stacks with Paramedic Training |
| 5 | Spotting Spies | Saboteur units become visible |
| 6 | Preemptive Strikes | Less dangerous to attack enemy units – 30% less danger |
| 7 | Increased Skills | Gain skills 1% faster per level, repeat |
The think you REALLY REALLY REALLY should explain is happyness system. How do church and bars work? What are those “+0.01 per day” made of? Does an active mission of bartend or preach make any difference? Please, Sarah, please please please!
I cant understand the happyness system, please give some advice, or some tutorial, rigth now i cant find any effect of building bars, or putting leaders in there it just seem random, but i almost sure i just dont get it.
Hi Sarah,
My name is Stephen. I have two questions. First, is probably the most popular question you have gotten, whether you’re creating another sequel in the Rebuild Series. The second is a tech or research tree for each individual. Like, would it be possible to have a randomized skill tree to develop for each person inside the fort? I mean it would be based and developed off of skill level and experience, but it would add so much more uniqueness to the game in general. Is this a possibility?