system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: why do games sometimes have glitches where their characters bend and stretch in surreal ways, phase through the ground, or vibrate uncontrollably?
gpt
Difficult to say. A character could have thousands of moving points, all working together through calculations. There could be quite a few reasons why those calculations don’t add up at that point. 

Maybe there’s an undividable number for some reason, some programming languages have floating point errors (weird bug where the result of a calculation is actually incorrect), but also simple human errors. 

Especially in an open world where literally everything can influence the character’s movement, it’s impossible to cover every single thing. It’s also impossible to test every single thing, because very often it’s not a single action that causes a bug, but a string of subsequent actions.

For simplification, imagine having 10 buttons, and 10 times you can press any button. That gives you 10^10 = 10 billion possibilities. That’s just 10 buttons and 10 actions. A game can have thousands of ‘buttons’ (things to interact with) and in theory an unlimited amount of subsequent actions.