Immunity Protocol Unit Types Guide: All Cell Classes

Overview of Unit Types

In Immunity Protocol, you command a squad of immune cell units, each with a unique combat role. Understanding these unit types is critical to surviving the escalating pathogen waves. There are four primary classes: Sentinel, Phagocyte, Lymphocyte, and Necrosis. Each unit type evolves as you progress, gaining new abilities and synergies.

Sentinel Class

The Sentinel is your starting unit, balanced for beginners. It features moderate health, steady automatic fire, and a basic shield ability. Sentinels excel at holding a position and providing covering fire. Upgrade their "Membrane Fortress" skill to increase damage resistance.

Key traits:

• Average movement speed
• Auto-targeting plasma bolts
• Active skill: Barrier Pulse (temporary invulnerability)

For more on early-game strategies, see our Beginner Guide.

Phagocyte Class

Phagocytes are melee-oriented units that absorb pathogens to heal themselves. They have high health but low range. Their "Engulf" ability instantly consumes a small enemy, restoring HP and granting a temporary attack boost.

Key traits:

• Short-range acid spray
• Passive: Regeneration on kill
• Active skill: Engulf (single-target execute)

Pair Phagocytes with ranged supports to maximize survivability. Check the Character Builds guide for synergy tips.

Lymphocyte Class

Lymphocytes are fragile but devastating ranged specialists. They fire piercing projectiles that can hit multiple enemies. Their "Antibody Burst" skill sends out a wave of homing missiles that weaken elite foes.

Key traits:

• High damage per second (DPS)
• Low health pool
• Active skill: Antibody Burst (AoE homing missiles)

Lymphocytes are essential for taking down Elite Enemies quickly.

Necrosis Class

The Necrosis unit type is a high-risk, high-reward class unlocked later in the game. It sacrifices health to deal massive area damage. Its "Decay Aura" drains nearby enemies while also slowly damaging the unit itself.

Key traits:

• Self-damaging abilities
• Large area-of-effect attacks
• Active skill: Decay Aura (damage over time aura)

Use Necrosis units with caution. The Progression Guide explains their unlock requirements.

Unit Evolution and Unlocks

All unit types can be evolved through the upgrade system. Each evolution tier adds new passive bonuses or modifies existing skills. For example, a Sentinel can evolve into a "Fortress Sentinel" with double shield duration.

For a full list of upgrades, refer to the Upgrades Guide.

Which Unit Type Should You Choose?

Your choice depends on your playstyle:

• Beginners: Start with Sentinel for its forgiving stats.
• Aggressive players: Phagocyte offers high sustain in melee combat.
• Tactical players: Lymphocyte provides pinpoint damage from a distance.
• Risk-takers: Necrosis delivers explosive power at a cost.

Experiment with different combinations to find your ideal squad. The Gameplay Overview has additional tips for forming a balanced team.