unit-retusa

Retusa is a water-only support unit in Mindustry that functions as a mobile repair platform with a secondary offensive capability. It appears in the naval support line (named after marine gastropods) and is intended to keep allied fleets and coastal defenses repaired while threatening nearby enemies with short-range torpedoes and a built-in laser. Retusa cannot traverse land and its primary role is sustain rather than frontline combat.

Retusa's armament and repair systems have changed over several builds. It currently mounts two weapons: a repair laser (two mounts firing at 1.36/sec each) that deals 12 damage per shot and repairs blocks for 5.5% of damage dealt, and water-bound homing torpedoes that fire at 2/sec, deal 1 base damage with a large area hit of 40 area damage (about 4.0 tiles), homing power 0.05, and an effective range extended to around 19 blocks in recent updates. Torpedoes are designed to operate in water and historically detonate or become ineffective when encountering solid land; some older versions detonated after a timed lifespan instead. The unit also provides continuous repair throughput to nearby allied units and structures (repair speed was set to 45 health/sec in past updates). The laser can target air units while the torpedoes remain water-bound and cannot target air.

In practice Retusa is used as a moving Repair Point for naval task forces: it heals allies quickly and keeps sustained fleets operational. Its torpedoes provide area-denial and soft anti-ship damage, but are limited by their inability to travel over land and by relatively low direct damage—therefore they are best viewed as harassment and crowd-control rather than primary anti-armor weapons. Retusa is outclassed in pure healing by some higher-tier support units (for example units that provide overclock fields or multiple repair points), but it occupies a niche as a cheap, fast-repairing, sea-only support.

• Positioning: since torpedoes detonate or fail when forced over land in many cases, enemies can negate much of Retusa's offensive capability by keeping targets two tiles away from the coast; Retusa is most effective operating fully on open water.
• Counters: high burst damage that kills Retusa before it can apply significant repairs is effective; turrets that can quickly two-shot or otherwise burst it down (Lancer was cited as an example) minimize its sustain impact.
• Synergy: pair Retusa with frontline naval units that benefit from continuous repair; it helps maintain unit pressure during long engagements but is less valuable where overclock or multiple-repair supports are available.
• History notes: Retusa began as sea mines in early builds, then shifted to timed detonating mines and later to water-bound torpedoes with homing and weaving movement. A laser repair weapon was added in later builds and its description and AI behavior have been adjusted across updates.