When you introduce a bug, is it a dumb random bug, or an intelligent AI bug? In other words, would the bug work for me or the user? When I say work for me, wh

When you introduce a bug, is it a dumb random bug, or an intelligent AI bug? In other words, would the bug work for me or the user? When I say work for me, what I mean is, considering decompiler tools like https://ghidra-sre.org/ https://ghidra-sre.org/ can shine light where once there wasn't, would the bug generates lots of unnecessary work for me, or could I use the bug as a stealth form of copy protection, where those with illegal copies get bitten by the bug and eventually forced into purchasing said code? I've seen that technique used with a software company supplying addons to other programming companies. Cant say its a technique taught at places like University.