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
In Ultima Online, you could buy all the house deeds from a vendor. The way they coded the economy, this caused demand to go up and you could then resell them to the vendor for a higher price. I stayed up for over 24 hours making millions doing this. The kicker was that gold actually had weight. You couldn’t move with 100k gold on you. You had to drop your gold on the ground, move a few spots, pick up your gold, and drop it a few spots in front you all the way to the bank.
To this day, I look for economy exploits like this in every game I play.
UO and early WoW were social experiments on how videogame economy was more real life like than any game designer wished, they had to make lots of adjustments to mimick inflation and supply and demand behavior