Lab Rat
Disposable melee pawn. Levels up whenever adjacent plots level up, with no max level.
- Type
- Troop
- Owner
- King of Progress
- Unlock the king
- Level up 299 plots
- HP
- 13
- Damage per hit
- 5
- Seconds between attacks
- 3
- Units
- 2
Level-1 values from the 1.0 game data, before perks, decrees, difficulty and level-ups. Playing the same card on the plot again levels it, normally to 3.
How players use it
- King of Progress Two sources, with different carries. Level-up chains explains Lab Rat, Concabulator and Overhaul.
- Level-up chains: Lab Rat, Concabulator and Overhaul Lab Rat levels up whenever an adjacent plot levels up, with no maximum level. A level-up next to one Rat therefore levels the Rat too, and if that Rat sits next to another Rat, the second one levels as well. The chain starts from anything that levels a plot: an upgrade, Wildcard, Overhaul, a level-3 Concabulator and, since Patch #29, Patronage.
- Uses Test an interaction before relying on it. For example, put a Lab Rat between two Concabulators to see how a level-up chain resolves, or check what Amplifier passes on from each support building.
- Quests changed late in Early Access and in 1.0 Progress 25: stronger starting Lab Rats (Patch #31).
How to get it
- In the King of Progress's 9-card deck: a run as this king can start with it, and losing a battle offers cards from your own deck.
- Loot after beating the King of Progress in battle when that king is one of your enemies.
- Merchant: Jack of Arms (troops).
- Joker mode: pick it for a custom deck.
Decrees, perks and cards that name it
| Entry | Effect |
|---|---|
| Splicing King of Progress decree | Doubles the level of all active Lab Rats. |
| Scientific King of Progress perk | Lab Rats start with extra levels. |
Rest of the King of Progress deck
Patch history
- Patch #18
Lab Rat base stats were increased while mildly decreasing upgrade %, for a more balanced and stronger early game.
- Patch #29
Lab Rat initial stats were buffed.
- Patch #29
Lab Rat chain effect is now also triggered by Patronage.
- Patch #29
Patronage now also triggers the Lab Rat chain effect.
- Patch #29
Increased Executioner and Lab Rat initial stats.
Lines from the official Steam patch notes since Patch #18 that name this card.
Achievements
- Ratticus the First: Get a Lab Rat to level 99.
Data: 9 Kings 1.0 card table on the official wiki, imported 2026-11-13.