Security 51 Endings Guide — Good, Bad, and Shift Map Routes

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After Day 30, restart at a marked crisis branch and build one solution through Isolation Ward experiments and City Operations. Existing saves remain Medium, while profile tool upgrades persist across repeat playthroughs.

After the first Day 30 ending, open the Shift Map and restart at the beginning of the crisis you want to change. For a good outcome, quarantine the matching anomaly type, run its Isolation Ward experiment, and repeatedly launch the City Operation with the strongest progress for that solution. The green solution bar must overtake the red crisis bar. For the corresponding bad ending, let the red bar reach its failure threshold instead.

The developer has confirmed the underlying rule: successful experiments unlock City Operations, the green solution progress must exceed the red problem progress, and whichever solution has the highest percentage shapes the later story and ending. That is the missing connection between the checkpoint, Isolation Ward and Shift Map.

Repeat-playthrough setup after the Endless update

Use the same save and Shift Map when you only want to change an ending branch. Existing save files remain on Medium, and the update does not add a difficulty switch to them.

Start a new game when you want to choose a different difficulty: Easy removes the shift timer, Medium uses the standard timer, and Hard gives less time with harsher penalties. Tool upgrades now belong to the player profile and persist across repeat playthroughs. After the first ending, the major update also disables tutorials on later playthroughs.

Endless Mode is a separate unlimited-shift mode that ends when sanity or hunger is fully depleted. It is not a replacement for the Shift Map route used to revisit campaign crises and collect alternate ending achievements.

What the Shift Map is asking you to change

Day 30 ends with the branching-timeline tutorial. The map is not asking you to replay a random ordinary inspection. It is asking you to return to a point where a crisis solution can still be changed.

1. Finish Day 30 and continue through the timeline cutscene.
2. Open the Shift Map after the tutorial.
3. Look for the current patch's question marks, borders and tooltips. They identify useful days for an alternate story branch.
4. Select the beginning of the crisis you want to change, not merely the last shift before its ending.
5. Build a different solution from that point by changing which infected people enter the ward, which experiments you complete and which City Operations you launch.

If you branch too late, the dominant solution may already be locked by earlier progress. A current developer reply recommends balancing the city by keeping green progress above red while allowing one chosen solution to become the highest. A current endings discussion gives the same practical advice: return to the start of the crisis and choose another solution path.

Early solutions and final outcomes are different

1. 01Which crisis stage?Read the branch and city problem before choosing the experiment.
2. 02Early floorEarly-floor solutionMatching infection choices open later crisis families.
3. 03Final good outcomeFinal good resolutionUse Machina Fatorum for each of the nine final outcomes.
4. 04Crisis winsCrisis collapseThe crisis wins when containment fails; verify the achievement screen.

Which crisis stage?→Early floorEarly-floor solutionWhich crisis stage?→Final good outcomeFinal good resolutionWhich crisis stage?→Crisis winsCrisis collapse

Read the route as text

1. Which crisis stage?Read the branch and city problem before choosing the experiment.
2. Early-floor solutionMatching infection choices open later crisis families.
3. Final good resolutionUse Machina Fatorum for each of the nine final outcomes.
4. Crisis collapseThe crisis wins when containment fails; verify the achievement screen.

Early-floor quarantine choices lead into different crisis families. The final nine good outcomes below use Machina Fatorum, not whichever early infection originally opened that branch. The illustrated achievement guide specifically requires experimenting on Machina Fatorum subjects and advancing its strongest related operation for these final resolutions. Resolve the second-floor anomaly paths to expose the final families; do not treat one Day 30 replay as completion of all nine.

Good-ending route

Use this sequence for each final crisis family, with Machina Fatorum as the final solution:

1. Read the current city problem. Identify the outbreak or crisis family shown by the branch.
2. Choose one intended solution. Do not split progress evenly between incompatible experiments if you are targeting a named outcome.
3. Quarantine Machina Fatorum subjects for the final good outcomes. Earlier crisis branches use their own solution types; do not confuse the stages.
4. Run the matching experiment every day it is available. A successful experiment unlocks or advances the related City Operation.
5. Launch the highest-progress matching City Operation. Keep that solution ahead of alternatives.
6. Keep green ahead of red. Solving the crisis requires solution progress to exceed the problem bar before the crisis wins.
7. Continue until the ending screen and achievement appear. Check which achievement registered before starting another branch.

The current achievement route identifies nine final Machina Fatorum resolutions:

Steam's public achievement list confirms these named outcomes. The route descriptions come from a current 100% achievement guide, while the developer explanation supplies the progress rule behind them.

Bad-ending route

Bad endings happen when the crisis wins. The cleanest replay method is:

1. Use the Shift Map to enter the crisis branch you want.
2. Stop launching City Operations for that crisis.
3. Continue shifts until the red problem bar reaches its failure threshold.
4. Let the collapse ending and its achievement register.

The current guide recommends earning the good version first, then replaying the last useful branch and withholding operations. At that point the crisis is already established, so the bad ending may take only a few additional shifts.

Named bad outcomes in the official achievement set include We Need a Disinfectant!, Ones and Zeroes, Remember Me!, Is That Megazord?!, Who You Gonna Call?, Are They Really Edible?, You Never Asked For It..., Augmented Humanity, and Cyberjurassic Park. Treat the achievement screen—not an unofficial ending nickname—as the completion signal.

World Saved: 1

The current achievement route reports that World Saved: 1 unlocks with the last of the nine good Machina Fatorum resolutions. In practical terms, clear every final crisis family through its green solution route instead of allowing the matching collapse outcome.

You do not need to guess which old day matters. Use the Shift Map indicators added by the current patch, branch near the start of a crisis, and change one solution at a time. That preserves cause and effect and avoids replaying an entire career for a branch that was already decided.

For the first timeline unlock and Day 30 transition, use the Security 51 Shift Map guide. Return to the Security 51 overview for platform, release and current answer links.

Sources & evidenceOpen the references used for this page

• Security 51 official Steam Community and current Shift Map patch notes
• Official Security 51 Endless Mode update
• Official major update with repeat-playthrough and Shift Map changes
• Developer explanation of experiments, solution progress and endings
• Official Security 51 Steam achievements
• Current Security 51 100% achievement guide
• Day 25–30 walkthrough and Branching Timeline unlock
• Current discussion of where to restart an ending branch