Slots are the real constraint
Dome Keeper has 26 gadgets but only 11 distinct slots, and at least one slot is explicitly single-occupancy. That changes the question: “best gadget” is not a ranking, it is a slot-by-slot decision.
The 11 slots, with what competes for each:
| Slot | Count | Candidates |
|---|---|---|
| Cellar | 7 | Blast Mining, Condenser, Drillbert, Iron Worms, Mushroom Farm, Resource Converter, Teleporter |
| Dome Surface | 4 | Auto Cannon, Buzz Saw, Dome Armor, Stun Laser |
| Primary | 4 | Droneyard, Orchard, Repellent, Shield |
| Keeper Suit | 3 | Prospecting Meter, Resource Packer, Suit Blaster |
| Mine Shaft | 2 | Drilling Rig, Underground Station |
| Cellar Dome Backside | 1 | Furnace |
| Shaft | 1 | Lift |
| Dome Backside | 1 | Spire |
| Dome Backside Secondary Combat | 1 | Missile Launcher |
| Dome Surface Secondary Combat | 1 | Shockwave Hammer |
| Cellar Keeper Suit | 1 | Probe |
Three of these are documented as exclusive in the wiki’s own text, and they are the three that matter most.
The Keeper Suit slot: three gadgets, one choice
This is the tightest decision in the game. The wiki states the Prospecting Meter takes up the sole Keeper Suit gadget slot, and the same slot holds Resource Packer and Suit Blaster.
- Prospecting Meter — by default shows the distance to any iron within 5 tiles. Pure information; useless once you know the map.
- Resource Packer — packs and compresses materials, which attacks the carry problem directly.
- Suit Blaster — explosively destroys blocks, and is one of the three gadgets the wiki names for Dense Iron.
The choice follows from the run: unknown map, take Prospecting Meter. Deep haul with a slow keeper, take Resource Packer. Dense rock, take Suit Blaster. You cannot take two.
Primary: four gadgets, one of which defends
The four primary gadgets are Droneyard, Orchard, Repellent and Shield. Only Shield is pure defence.
Shield absorbs incoming damage until depleted, then automatically recharges to full at the end of the wave, in time for the next one. That timing is what makes it strong: it is not a consumable, it is a guaranteed buffer every wave, and it rewards a dome that survives rather than one that kills fast.
The other three are economy and control: Droneyard produces drones for resource transport, Orchard grows fruit for temporary buffs, Repellent produces monster-repelling liquid on demand.
Dome Surface: four weapons, and the Auto Cannon question
Auto Cannon, Buzz Saw, Stun Laser and Dome Armor share the dome surface slot group. Three of them are ways to kill things and one is a way to not die.
Auto Cannon installs an automatic cannon that does heavy damage — the wiki’s description stops there, so treat it as a damage upgrade rather than a mechanic. Stun Laser auto-targets and stuns, which is control rather than damage. Buzz Saw runs along the cupola hitting anything adjacent. Dome Armor is plating.
For “Auto Cannon best upgrade” queries, the honest answer is that its value depends on the dome rather than on a hidden upgrade path: it is a damage source on a surface slot, and surface slots are contested by crowd control (Stun Laser) and survivability (Dome Armor).
Assignments with documented answers
Three assignments have specific gadget recommendations the wiki states outright, and they are the most actionable picks in the game:
| Assignment | Recommended | Why |
|---|---|---|
| Dense Iron | Iron Worms, Blast Mining, Suit Blaster | Rock density resists normal mining |
| Dense Iron (Assessor) | Explode Spheres, 6 Iron at start | Cheapest opening solution |
| Iron Contribution | Resource Converter | Rebalances resources toward iron |
| Defective Weapon | Artillery dome (most health) | You cannot shoot, so health is the only lever |
That table is the closest thing to a tier list the game supports. Everything else is slot economics.
A slot allocation that works
- Keeper Suit: Prospecting Meter on your first ten runs. Knowing where iron is beats every other early advantage.
- Primary: Shield once waves start hurting. A full recharge every wave is worth more than a passive economy gadget.
- Cellar: one production gadget, not four. Iron Worms or Resource Converter, matched to the map’s problem.
- Dome Surface: match the assignment. Stun Laser for Projectile Hell, Dome Armor for Defective Weapon, Auto Cannon for general damage.
- Fill the single-slot exotics last — Furnace, Lift, Spire, Missile Launcher, Shockwave Hammer and Probe are each alone in their slot, so they never compete with anything except your iron.
Related guides
- Dome Keeper Gadgets Database — all 26 gadgets in a filterable table
- Dome Keeper Guild Assignments Guide — all 25 assignments and their conditions
- Dome Keeper Characters Guide — which keeper suits which slot economy
- Dome Keeper Mechanics Guide — the three upgrade paths and how to heal
- Dome Keeper Hub — all guides for this game