Be a Pirate! Swarm Rats: Rat Catcher & Rat King Guide

Swarm Rats Achievement Targets

Five hundred rats in a single battle earns one achievement; reaching 10,000 earns another. Be a Pirate! Swarm Rats give you two distinct goals: Rat Catcher rewards a concentrated hunt, while Rat King rewards your cumulative total. Keep the single-battle requirement in mind before spreading your efforts across multiple fights.

Achievement	Rats Required	Counting Requirement
Rat Catcher	500	Within a single battle
Rat King	10,000	Cumulative total

For Rat Catcher, focus on reaching the entire threshold during the same battle. Defeating 500 rats across separate battles contributes toward Rat King, but it does not satisfy Rat Catcher’s condition.

For Rat King, work toward the larger total across your battles. Separate that ongoing goal from attempts specifically aimed at the 500-rat milestone.

Neither rat achievement includes a named map or difficulty requirement in its condition. Other combat achievements do attach those restrictions: Skeleton Crew requires a victory from Map 8 onward on Deckhand or Captain with no more than 10 attacking towers built. Keep those separate conditions in mind if you decide to combine objectives during a battle.

Thunder and Brimstone sets a different combat target: sink 40 enemies within 2 seconds. That achievement measures a burst of eliminations, while Rat Catcher measures rats defeated throughout one battle. Plan around the requirement you are pursuing; reaching a large battle total and defeating a tightly timed group are separate accomplishments.

Endless mode also has its own survival milestones. Beyond the Horizon requires surviving 20 waves, Charts Fade requires 30, Compasses Falter requires 40, and Stars Forget requires 55. Some Ships Do Not Return extends the challenge to surviving 30 Endless waves on all 15 maps. Keep these wave counts separate from your rat tally: surviving waves and sinking rats measure different things.

Official page: Be a Pirate! (store.steampowered.com)

Shape Your Defenses Around Both Attack Routes

A rat-focused objective still sits inside a battle fought on land and water. Ground enemies change their route around your structures, while Crown Sloops follow the river. Build with both routes in mind so your achievement attempt has defenses covering each approach.

Image: Steam / Noble Rogues

Use these mechanics when planning your layout:

• Extend the ground route deliberately. Use tower placement to encourage a longer march through your defenses, then reassess the route after building.
• Maintain river coverage. A Bridge creates a crossing for land traffic, but Crown Sloops continue underneath it. Keep towers positioned to engage the water route.
• Check elevation when choosing positions. Terrain height affects tower placement and results, so consider height alongside the route itself.
• Spend Doubloons on the coverage you need. Towers have four upgrade tracks: Offense, Range, Specialty, and Signature. Choose upgrades that address the part of the battle putting pressure on your ship.

Elemental matchups also matter throughout combat: Physical, Fire, Ice, Electric, and Poison interact with enemy resistances and weaknesses. Match your damage choices to the enemies you face instead of choosing an element solely because you are pursuing a rat achievement.

The Commodore’s Flag strengthens nearby towers. Place it where its surrounding damage boost can support the attacking towers covering your chosen routes.

Tower choices include the Cannon, the poison-focused Voodoo Cauldron, and the beam-focused Heliograph Battery. Each tower’s Specialty track is specific to that tower, while its Signature ability changes how it fights. Compare those functions with the coverage your layout needs before spending more Doubloons. Fully Rigged provides an additional upgrade objective: purchase all 20 battle upgrades for one tower.

Route building has a measurable achievement target, too. The Long Way Round requires stretching the enemies’ march to three times its starting length. Use that objective when practicing layouts that redirect ground traffic. For a separate construction challenge, No Walls, No Problem requires winning from Map 8 onward without building a palisade.

Old Faithful adds another restriction from Map 6 onward: win with only one kind of attacking tower. Palisades, bridges, and the Commodore’s Flag are excluded from that count. Preserve that distinction when planning a combined achievement attempt; support structures and attacking tower variety have different roles in this challenge.

Captain selection also affects preparation. The game has 15 recruitable Pirate Captains with permanent bonuses, equipment, and upgrade paths, and your active captain accompanies your ship into battle. Review those bonuses alongside your tower choices. Home Waters offers a separate captain objective: win on Captain difficulty with the captain associated with that map in command.