system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 : How are game engines made and why are they necessary for games and why are there so many of those?
gpt
A game engine is a lot of reusable code that different game studios can use to make their games.

Game development teams do not want to spend a lot of time reinventing the wheel with each game. Rewriting code on how to handle physics, how to handle a hitscan bullet, how to handle a projectile weapon, etc. This code is essentially going to be the same in every game that uses them, so why spend a lot of time writing it for each project?

This leaves the game developers the time to actually code the stuff that makes their game *different* from others.