The skill tree
Every bunker level gives you one skill point. Spend them wisely: there are six branches and each one improves something different.
Six branches
Energy, Survival, Engineering, Combat, Exploration and Mining. Each branch has up to six technologies that give more scrap, more experience, shorter waits, more health on expeditions, more loot, more ore in the mine and much more.
How they unlock
The technologies in each branch open one at a time. To move up to the next tier you must have spent a total number of points: 2, 5, 9, 14 and 20 for tiers 2 to 6.
Points cannot be bought
Skill points are only earned by levelling up through tasks: they cannot be bought or exchanged for money. Nobody gets an advantage by paying.