Immunity Protocol Endings Guide: All Outcomes Explained

Overview of Immunity Protocol Endings

Immunity Protocol features multiple endings that depend on your choices, progression, and how you manage the collapsing biological system. The game tracks key decisions made during campaign runs, your relationship with certain symbiotic units, and the total number of pathogen waves you survive. There are three primary endings: the Standard Ending, the True Ending, and the Bad Ending. Each requires specific conditions to be met before the final boss encounter. Understanding these requirements early can save you hours of replaying.

Standard Ending Requirements

The Standard Ending is the default outcome if you defeat the final boss without fulfilling special conditions. To reach this ending, you must:

• Survive all 20 pathogen waves in the campaign
• Defeat the final boss, the "Prion Nexus"
• Complete the campaign without triggering any hidden events

This ending provides a straightforward conclusion where the immune system stabilizes temporarily, but the narrative hints at further corruption. Most players will see this on their first playthrough. It serves as a baseline for understanding the game's story before pursuing the more complex endings.

How to Unlock the True Ending

The True Ending requires careful planning and specific upgrades. You must:

• Fully evolve your weapon to tier 5 before wave 15
• Collect all 3 hidden "Memory Fragments" scattered across biomes
• Equip the "Symbiotic Core" upgrade during the final boss fight
• Maintain at least 80% health during the Prion Nexus encounter

The Memory Fragments are located in secret rooms accessible only after unlocking the Secrets Guide. The Symbiotic Core becomes available after you complete the Upgrades Guide objectives. If you meet all conditions, the final cutscene reveals the true origin of the pathogen and the immune system's full recovery.

Bad Ending Triggers

The Bad Ending occurs when you fail critical objectives or make detrimental choices. Triggers include:

• Losing all symbiotic units before wave 10
• Failing to upgrade your weapon past tier 2 by wave 18
• Accepting the "Corrupted Pact" event offer from the shadow entity
• Dying more than 3 times in a single run

If you trigger the Bad Ending, the biological system collapses completely, and the pathogen spreads unchecked. This ending is deliberately grim and serves as a cautionary tale. You can avoid it by following the Beginner Tips guide and prioritizing symbiotic relationships.

Secret Ending Discovery

A hidden fourth ending exists, known as the "Protocol Reset" ending. To unlock it:

• Complete the game on the hardest difficulty setting
• Defeat the final boss without taking any damage
• Use only starter equipment throughout the entire run
• Interact with the terminal in the final arena three times before the boss fight

This ending is extremely difficult and requires mastery of movement and auto-fire timing. Refer to the Difficulty Guide for strategies to survive the hardest waves. The Secret Ending reveals a fourth-wall-breaking message about the nature of the simulation.

Ending Impact on New Game Plus

Each ending affects your New Game Plus run differently:

• Standard Ending: Resets progress but grants a 10% damage bonus
• True Ending: Carries over all upgrades and unlocks a new biome
• Bad Ending: Locks certain upgrades until you complete a redemption run
• Secret Ending: Unlocks the "Debug Mode" modifier for future runs

The Progression System guide explains how endings influence your long-term save file. Choose your ending carefully based on your goals for subsequent playthroughs.

Frequently Asked Questions

Can I get all endings in one playthrough? No, each ending requires specific conditions that cannot be met simultaneously. You need at least 4 runs to see all endings.

Does difficulty affect endings? Only the Secret Ending requires a specific difficulty. Other endings are accessible on any difficulty setting.

Will my choices during the campaign lock me out of endings? Yes, accepting the Corrupted Pact event permanently locks you out of the True Ending for that run.

Is there a post-credits scene? The True Ending has a post-credits scene that hints at a sequel. The other endings do not.

Can I replay the final boss to change my ending? No, the ending is determined by your entire run. You must start a new campaign to pursue a different outcome.