Friendly Fire

Definitions

Damage caused accidentally by your own side, borrowed from military language and used metaphorically in tech for internal mistakes or cross-team harm. In engineering culture it often describes outages, broken assumptions, or process changes that hurt the very people meant to benefit from them.
In plain English: Accidental harm caused by your own side or team.
Example: "The refactor created classic friendly fire when a cleanup meant for maintainability broke the internal support tools that depended on undocumented behavior."