Read the end node first
Find the upgrade you want at the end of a path, then work backwards. That tells you which early nodes are mandatory and which are a distraction. Buying forward from the start and hoping it connects is how points get wasted on nodes you never use.
Gates
Some later upgrades only appear after earlier ones. Missing that chain means either paying for nodes you did not want or never reaching the payoff. The upgrades guide covers which lines compound; this page is about not locking yourself out.
Mutually exclusive branches
Several gadget trees force a real choice — picking one closes the other:
- Orchard (Primary, Buff) — two battle abilities are mutually exclusive: roots that trap medium monsters, or branches that shield the dome from projectiles.
- Shield (Primary, Defensive) — three battle abilities are mutually exclusive: an electro-blast field, brief invulnerability, or projectile reflection.
- Droneyard (Primary, Utility) — two combat-drone paths are mutually exclusive: the autonomous Battle Grid (shoots during waves) or Parasitic Drones (attach to and stun the largest monster).
Because all three live in the generous Primary slot (which has four spaces), you can still run Orchard, Shield, Droneyard and Repellent together — but within each you must commit.
Gadgets versus upgrades
Gadgets are immediate; upgrades compound. A run that buys only gadgets stalls once waves outscale the flat help, and a run that buys only upgrades gets overwhelmed before the compounding kicks in. The tree is where you choose which compounding you want; the gadgets guide is where you fill the immediate gaps.
Related guides
- Upgrades Guide — spending what you mine.
- Gadgets Guide — immediate help to pair with the tree.
- Dome and Keeper Guide — which start the tree should serve.