Structure trees

You spend a shared balance of structure upgrade points across 6 trees, choosing between higher building tiers and additional build items. You begin with 2 structure trees unlocked, so spending points in other trees leaves your starter walls and miners available.

How it works

Each selection spends 1 structure point without charging resources. Placement still charges the build cost. The Choose next upgrade list offers an item only when you have a point, meet its level requirement and have its preceding tier, if any.

A higher tier replaces the preceding build item in your hotbar and, if equipped, in your hand. Placed structures keep their tier. Your 32-wall allowance, for example, counts your walls across every tier. These building limits count each player’s placements separately. Spending a point does not free a place or change an existing structure.

Structure point levels	3, 4, 6, 8, 10, 12, 13, 15, 16, 17, 18, 19
Total structure points	12

Walls

You start with the Wooden Wall. The next tiers, the Stone Wall and Reinforced Stone Wall, replace it in sequence, taking 2 points to finish the tree.

Wooden WallStart
- Stone WallLv 3
  - Reinforced Stone WallLv 10

Wall	Placement cost	Health
Wooden Wall	50 wood	350
Stone Wall	50 wood, 100 stone	700
Reinforced Stone Wall	100 gold, 50 wood, 100 stone	1400

Miners

You also start with the Wooden Miner. The next tiers, the Stone Miner and Reinforced Stone Miner, replace it in sequence. Miners produce gold while you are alive. The table shows their base production without a gold mine bonus; see Miners for placement bonuses.

Wooden MinerStart
- Stone MinerLv 4
  - Reinforced Stone MinerLv 10

Miner	Placement cost	Base gold per second
Wooden Miner	10 wood	2 gold
Stone Miner	10 wood, 20 stone	4 gold
Reinforced Stone Miner	100 gold, 20 wood, 40 stone	5 gold

Spikes

There is no starter spike. You unlock the Wooden Spike, then the Stone Spike, then the Reinforced Stone Spike, spending 3 points to finish. You cannot skip a tier by saving points until its level requirement is met; each selection requires the preceding spike build item.

Wooden SpikeLv 3
- Stone SpikeLv 6
  - Reinforced Stone SpikeLv 10

Structure	Health	Cost	Limit	Base destroy reward
Wooden Spike	120	20 wood	16	10 wood, 10 experience
Stone Spike	200	20 wood, 50 stone	16	10 wood, 25 stone, 20 experience
Reinforced Stone Spike	300	100 gold, 60 wood, 120 stone	16	50 gold, 30 wood, 60 stone, 40 experience

Turrets

There is no starter turret. The Wooden Turret leads to the Stone Turret and Reinforced Stone Turret.

Wooden TurretLv 4
- Stone TurretLv 6
  - Reinforced Stone TurretLv 10

Structure	Health	Cost	Limit	Base destroy reward
Wooden Turret	60	50 wood	4	25 wood, 10 experience
Stone Turret	120	50 wood, 100 stone	4	25 wood, 50 stone, 20 experience
Reinforced Stone Turret	180	100 gold, 100 wood, 200 stone	4	50 gold, 50 wood, 100 stone, 40 experience

Pads

You can choose only 1 of the 4 alternatives. The options are the Repair Pad, Health Pad, the TNT or Landmine. Selecting any of them removes every other pad-tree choice for that life. More points do not let you add another choice or switch the selected build item; respawn resets the selection.

Structure	Placement cost	Active limit
Repair Pad	30 wood	4
Health Pad	30 wood	4
TNT	400 gold, 250 wood, 250 stone	3
Landmine	100 gold	12

Other

You can choose only 1 of the 3 alternatives. The options are the Anti Structure Pad, Speed Boost or Honeycomb. Choosing Honeycomb still rules out the pads in this tree for that life, while leaving your pad-tree choice available.

Structure	Placement cost	Active limit
Anti Structure Pad	40 wood	2
Speed Boost	30 wood, 30 stone	16
Honeycomb	30 wood	8

Tips

Compare placement costs before unlocking a build item. A wall or miner upgrade removes the cheaper tier from your hotbar, even when you cannot afford to place its replacement.
Keep lower-tier structures until you need their places. An upgrade leaves them intact, and destroying a structure frees its place for the higher tier; upgrading alone frees no places.