Rat Swarm
Rat Swarm is Rat King's second ability in Deadlock (slot 2), an active ability with a 24 second cooldown. Call forth a swarm of rats that leap onto enemies, dealing spirit damage over time and reducing their bullet resist with every bite. The more rats are attached, the faster they will bite the target.
Open the most-bought Rat King build
The 4 items bought most in each phase of 202,752 Rat King matches, October 30 to November 1, 2026, measured by deadlock-api.com.
Rat Swarm in matches
Rat King players unlocked Rat Swarm third in 61.6% of matches (125,533 of 203,801), second in 35.3% of matches (71,872 of 203,801), first in 2.8% of matches (5,733 of 203,801) and last (fourth) in 0.3% of matches (571 of 203,801), in all-rank matches from October 30 to November 1, 2026, from patch 6833's release day.
Measured from matches at all ranks from October 30 to November 1, 2026, starting on the day patch 6833 was released (October 30, 2026), by deadlock-api.com. These are match results, not numbers from the game files, and not a recommendation. Each share is the Rat King matches in which Rat Swarm was the first, second, third or fourth ability unlocked, out of every Rat King match counted; a step under 500 matches is not listed.
Match data: deadlock-api.com. deadlock-api.com is not endorsed by Valve and does not reflect the views or opinions of Valve or anyone officially involved in producing or managing Valve properties. How a share is computed: methodology.
Rat Swarm stats
Rat Swarm
- Cooldown 24s
- Charges 1
- Between charges 8s
- Duration 6s
- Range 50m
Call forth a swarm of rats that leap onto enemies, dealing spirit damage over time and reducing their bullet resist with every bite. The more rats are attached, the faster they will bite the target.
Enemies can have multiple rats attached, but can shake off a rat early by performing a ground or air dash.
- 1s Bite Interval per Rat
- 4s Debuff Duration
- 5 Max Attached Rats
Upgrades
| Tier | Bonuses | In game |
|---|---|---|
| 1 | +1 Charge | |
| 2 | +2 Rat Swarm Cols +1 Rat Swarm Rows +100 Rat Swarm Width +4s Debuff Duration | Increased Swarm Size +4s Debuff Duration |
| 3 | -1% Bullet Resist per Bite +8 Damage per Bite | +8 Damage and -1% Bullet Resist per Bite |
Each tier is bought with ability points; how many points a tier costs is not in the game files this site reads, so it is not shown. Learning the ability takes 1 ability unlock.
Rat Swarm change history
| Patch | Change | State |
|---|---|---|
| November 5, 2026build 6860from build 6757 | No player-facing change in 33 builds (October 6 to November 5, 2026). | Unchanged |
| October 5, 2026build 6753 | Rat Swarm's cooldown changed from 28s to 24s. | Changed |
| October 2, 2026build 6742 | Added to Deadlock. | Added |
Rat Swarm FAQ
What does Rat Swarm do?
Call forth a swarm of rats that leap onto enemies, dealing spirit damage over time and reducing their bullet resist with every bite. The more rats are attached, the faster they will bite the target. Enemies can have multiple rats attached, but can shake off a rat early by performing a ground or air dash. Its tooltip lists 8 Damage per Bite (+0.08 x Spirit), -1% Bullet Resist per Bite, 1s Bite Interval per Rat and 4s Debuff Duration.
What is Rat Swarm's cooldown in Deadlock?
Rat Swarm has a 24 second cooldown.
How does Rat Swarm scale with spirit power?
Damage per Bite starts at 8 and gains 0.08 per point of Spirit, the coefficient the game file writes on the value.
What do Rat Swarm's upgrades do?
Tier 1: +1 Charge. Tier 2: Increased Swarm Size, +4s Debuff Duration. Tier 3: +8 Damage and -1% Bullet Resist per Bite.
When was Rat Swarm added to Deadlock?
Rat Swarm was added to Deadlock in the October 2, 2026 patch (build 6742).
Was Rat Swarm changed in the latest patch?
No. Rat Swarm is unchanged in the latest build of Deadlock on file (the November 5, 2026 patch, build 6860). It last changed in the October 5, 2026 patch.