Modifiers can be placed on platform tiles instead of towers. They affect the surrounding 8 tiles with various beneficial effects, though often with certain trade-offs as well. They're also more economically flexible than towers, being sellable for greater percentages of their original costs than towers generally are - they can be sold for their full price 5 minutes after placing them. If sold earlier, they will return 75% of the coins.
Modifiers can be unlocked most commonly via Research, where upgrades to the quantity and quality of each can be purchased; and less commonly via specific Trophies.
Modifier price increases for each matching modifier already in play, with compounding cost increases that vary by type (details for each type are provided below).
Evenly distributes experience between surrounding towers
Doesn't diminish experience if this leads to a decrease of tower's level
Rate of xp transfer per second increases with level (at a cost of xp)
Prices:
Mod#
1
2
3
4
5
6
7
8
9
10
Cost
25
35
50
70
95
135
190
265
370
520
Transfer Rates and Upgrade Costs:
Upgrade Level
XP/sec
Next Lvl XP cost @base, @max res.
1
3
150
135
2
7
600
540
3
15
2000
1800
4
35
5000
4500
5
100
N/A
N/A
Search[]
With SEARCH, surrounding towers will constantly search for new enemies, even if their current target is still alive
Increases tower range by 4% (upgradable to 5% in Normal and 9% in Endless)
Prices:
Mod#
1
2
3
4
5
6
7
8
9
10
Cost
50
70
95
135
190
270
375
530
740
1030
Power[]
Gives +5% PWR (upgradable to 8% in Normal and 28% in Endless, with +1.2% more available in Star Research) to all nearby towers
Consumes 1 XP/s of the most experienced tower for bonus of each tower. Doesn't diminish experience if this leads to a decrease of tower's level
PWR increases all common (non-gold) characteristics except range
Mod#
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Cost
100
150
225
335
510
760
1140
1710
2560
3840
5750
8650
12950
19450
Damage[]
Increases damage of towers on the sides by 15% (upgradable to 21% in Normal and 53% in Endless)
Decreases attack speed of towers on the corners by 5%
Prices:
Mod#
1
2
3
4
5
6
7
8
9
10
Cost
100
150
225
335
510
760
1140
1710
2560
3840
Attack Speed[]
Increases attack speed of towers on the sides by 15% (upgradable to 22% in Normal and 53% in Endless, with +1.5% more available in Star Research and 1% more in Trophies)
Decreases damage of towers on the corners by 5%
Prices:
Mod#
1
2
3
4
5
6
7
8
9
10
Cost
100
150
225
335
510
760
1140
1710
2560
3840
Mining Speed[]
Gives +20% (upgradable to 35% in Normal and 195% in Endless, with +6% more available in Star Research) to the mining speed of nearby miners
Reduces Rotation and Projectile speed of nearby towers by 5%
Prices:
Mod#
1
2
3
4
5
6
7
8
9
10
11
12
Cost
120
195
320
530
860
1420
2320
3800
6200
10200
16700
27350
Bounty[]
Gives bonus 2% of player's current coins, but not more than 50 coins (upgradable to 60 coins in Normal and 100 coins in Endless, with +5 coins more available in Star Research), each time an enemy wave is completely defeated.
Surrounding towers don't gain coins for killed enemies
Cost also increases with map difficulty
See Bounty tactics for details on costs and optimal purchase points
Minimum Prices (≤100% difficulty):
Mod#
1
2
3
4
5
6
7
8
9
10
11
12
Cost
180
310
530
910
1560
2690
4610
7900
13600
23350
40050
68750
Experience[]
When a resource is mined by a neighbouring miner, shares 20 XP (upgradable to 30XP in Normal and 70XP in Endless, with +2XP more available in Star Research) between surrounding towers
Takes 1 cheapest resource from each neighbouring miner every 10 seconds