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Curiosity about old Undertale tricks is surging again as speedrun clips highlight secret paths.
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Undertale's Mercy Button Secret: Why Your SAVE File is a Lie is a hidden flag in memory. Undertale's Mercy Button Secret is evidence your save is faking neutrality. Studies indicate choices you believe in may already be predetermined by early mercy use.
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This flag flips when you spare bosses early in the run. Mercy conditions later encounters, locking peaceful routes before you realize. Research shows timing of sparing shapes which scenes trigger.
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Fighting resets the hidden flag, clearing prior mercy actions. Precision here reshapes routes, showing mercy is more than compassion.
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What does this mean for my save files?
Your save shows mercy outcomes because early choices already mark routes.
Why should I care about hidden flags?
Understanding flags helps plan neutral routes and reset conditions for different endings.
