When in the city of Moresby (if if in the event you have made it there), you know that there are hordes of zombies and dumb thugs, suiciders, rams, and infected people. If you health is low and you need to regain self-awareness, jump on a car. The set of weapons you have out my be running on durability, or you need to check your map for some quests, or you just need to slow down and take a look around. Cars will help you very much. It could also help you kill the the walkers, and other things that are chasing you. It is kind of a glitch, because if you are on top of a car they will try to hit you but they can't. So you can take the liberty of shooting, slamming, slicing, or throwing at the walkers. You can basically do it with anything, I know that you can do it on the resort because of the amount of cars, but there aren't very many groups of walkers near the street. You can't reply do it in the jungle, because there aren't any cars broken down, and by all common sense, there are no cars in the prison.

Go to the warehouse, and get the Hammer and Baseball Bat. Then, fast travel to the Church, and sell them to get approximately $400. Go back to the Warehouse, and the Hammer and Baseball Bat will have respawned. Repeat this as many times as desired. Note: You must be in the City and have discovered both the Church and the Warehouse to do this trick.

Pull out the weapon you want to duplicate and wield it. In digital fighting control scheme, hold the left trigger as if to throw the weapon, hit the Y button at the same time as you pull the right trigger to throw the weapon, if you time it right you will throw your weapon and drop a second copy at whatever the current durability of the weapon you dropped was. As a bonus keep double of your favorite weapon and use until it breaks, discard and copy the fully repaired version to ensure your never stuck with a broken weapon.

MOD EDIT: This exploit has been patched with the version 1.3.0 patch.

This MUST be done in solo mode: When you reach a checkpoint during any campaign quest drop the item on the ground you wish to duplicate(Can be your all your items in your inventory). Then kill yourself by using deobombs or molotovs, When the respawn timer begins to countdown pause the game and reload your checkpoint. When you respawn all the weapons you dropped will be back in your inventory and they will also still be laying on the ground where you dropped them. Side note: you also do not suffer the cash penalty from dying since you reloaded the checkpoint.

If you go up to any car that isn't completely demolished, read what the license plate says. It says dead island in numbers and letters.