Way back in the late 90’s my idiot teenager self did in three ways on some early fps online games..
1) I abused an application that highered your windows speed in someway that allowed you to go incredibly fast in games like Quake 2 and half life 1 before they patched stuff out. You could put the app at 300% for example and go 3 times the speed on servers and just terrorize people because the server code had no movement limiting check so it just let the client side tell it where they were on the map. Early Counter strike 0.# was even better as the way valve handled server side bans early on was add it to a Client side .ini file where if an admin banned you for cheating I was able to simply delete that file and go back in and continue harassing the server. Fun fact, my user name came from this as I would hit the console ~ key, change from my old name Smucky to Sp3eD and hit the booster app. As awful as what I did was, I liked the “l33t” name I created.
2) this one was pretty bad. in the original quake mod team fortress (this was before valve bought the mod team and threw it on half life) there was a exploit you could download that allowed a spectator in a game to become an invisible / invincible neutral character on the map. While some classes were straight forward and gave you away such as soldier and pyro (the players could see your projectiles coming out of nowhere and moved around like a normal player so the jig was up almost immediately.) the best class for this was the medic. You could go to either teams base, get behind a player and hit them with your axe to cause them to get infected. It was absolutely hilarious to watch players spin around looking for who infected them in an empty room / long flag hallway while lighting the game chat up with cursing and slurs trying to figure out what was happening. As it became better known anybody sitting in spectator was called out or banned quickly and ultimately It was patched out pretty quick after it became rampant, but the invisible medic was something I remember vividly to this day.
3) Finally, this was an in game exploit back in CS 1.6, but I learned how to bunny hop before they patched it out. You could put jump to your mouse wheel, then spun it every single time you landed while moving side to side in a swooping motion to gain crazy speed. You could be to various enemy doors WAY before you were supposed to and surprise the other team with grenades or AWP shots. It was hard to master, but it was so fun to do once you got good at it. De-dust 1 and 2 maps were the best ones by far due to where you could get to on the maps first. Huge advantage.
After this era of pc shooters I moved over to console only pretty much so I left that life behind me. I was a piece of shit for doing that and I admit it. Kids, don’t be like me back then.