Economy structures
Gold Mines fund every tower upgrade. Building towers before economy feels safer but starves later days. Place income on safe circles first, then add chokepoint DPS.
Night failures from insufficient upgrades often trace to day-one economy skips. Read the tower defense guide for full day-night planning.
Defensive towers
Machine Gun Towers excel at sustained chokepoint damage. Infantry Camps help single-target elites. EMP Towers disable groups — pair with Mir and Energy heroes from the EMP support profile.
Upgrade one tower deeply before spreading new level-one structures unless new leak lanes open.
Fortress evolution
Survived nights evolve walls, laser cannons, and decoys. Evolution rewards long-term accounts that stabilize early chapters instead of rushing fragile pushes.
Mode-specific picks in the best buildings guide and Arena notes in equipment Arena guide.