How to approach the Bomb Farm skill tree
Updated 2026-09-01
On this page
The Bomb Farm skill tree spends Gold on upgrades for your whole squad; it does not spend hero ability points or Skill Stones. If a ready hero is waiting because your starting field slot is full, the first Field Slot purchase is a concrete early option: it lets a second hero fight.
Open Abilities to inspect the account's skill tree. A connected node must already be purchased before you can continue along a branch, and some nodes also require stage progress. Individual hero abilities are a separate system, with 20 abilities that can each reach level 10.
Pick a problem before a branch
The center, Detonation Reactor, is active from the start. These two nearby purchases address different problems; their values come from the official skill tree checked on September 1, 2026.
| Early purchase | Cost and effect | Requirement and useful situation |
|---|---|---|
| First Field Slot | 3,000 Gold once; adds one place, raising field capacity from 1 to 2. | Connected to Detonation Reactor, with no additional stage gate. Useful when another enabled, rested hero is waiting for space. |
| First Squad Damage node beside the center | 3,000 Gold for level 1; adds 0.5% squad damage at that level. | Also requires Detonation Reactor, with no additional stage gate. Improves damage without adding room for another hero. |
Select the node and match its effect, cost, and connection before purchasing. Several nodes share the same name, so Field Slot +1, taking capacity to 2 identifies the first unlock more reliably than the name alone. After buying it, check the increased capacity in Battle and whether a ready hero fills the new place. An extra slot does not restore an exhausted hero's energy.
For later branches, compare the full route cost, not only the final bonus. Undoing a purchase returns 50% of the Gold paid, and purchased child nodes must be removed before their parent. The first 3,000-Gold Field Slot therefore has a 1,500-Gold refund; experimenting is not free.
Older tree screenshots can point to different rewards
The August 15 playtest update changed two bag-tab nodes into Luck and Gold per Target. It also moved the Rare Find unlock to Normal difficulty and adjusted costs and bonuses in affected branches.
Those are dated playtest changes, so check the current skill tree node before following an old route. If a screenshot promises storage but your client shows an income bonus, use the client's description for your decision.
The same update introduced first-clear rewards across the campaign, with some X-10 stages offering rewards such as Skill Stones or House Chests. Open the Map and stage rewards when you need to see what your next clear offers.
Skill Stones reroll hero abilities
Skill Stones reroll an individual hero's abilities. The stone must match the hero's rarity, and the operation consumes one stone plus Gold. Take the hero out of Battle first, then inspect the reroll cost and confirmation for that hero.
The reroll replaces the hero's ability set and does not return abilities it already had. That does not guarantee a better set for your team, and the stone is consumed even if you dislike the result. Buying a skill tree node leaves those individual abilities unchanged.
Compare one change at a time
Choose a stage you know, keep the same team and equipment, and observe what changes after the upgrade. If you simultaneously replace two heroes, raise the difficulty, and buy a tree node, you will not know which decision changed the result.
Read each hero ability's scope as well. A description that affects only its owner should not be treated as a permanent team-wide tree bonus.
Sources: Official skill tree and node costs; Official ability-reroll rules (checked September 1, 2026); Steam store; August 15 developer playtest notes.