When I was playing dying light with friend we discovered that every timw you go to sleep and wake up air drop will appear, if you don’t know air drops are pretty rare and if you collext them and deliver to one guy you will recieve lots of xp, we used that multiple times to unlock grapling hook very early. Air drops also gave lots of medicine which was hard to get in early game and that very helped us
Oblivion also had an exploit I stumbled upon as a kid where you could duplicate items by dropping them from your inventory and releasing an arrow at the same time. It duplicated the item dropped for each arrow in the stack. This was before I really knew how to use the internet to look things up so I abused the crap out of that exploit.