In Dead Island for the PC, PS3, and Xbox 360, there are a couple different ways to duplicate items.
These may, and probably will be patched at some point, so avoid updating your game if you plan to use these in the future.
Craftable Item Duplication Glitch
This particular duplication method was done by crafting the Deo-Bomb, and I’m uncertain if it works on other craft-able items or not.
Quick travel to an area that sells parts for the Deo-Bomb. You gain the Deo-Bomb blueprint in Act 2 during the “Market Journey” quest, and it only requires deodorant and duct tape to create.
Once you make thirty Deo-Bombs, every bomb you make after that will create another stack of thirty. Sell these for some easy money.
Duplicate Any Item Glitch
This can only be done in the single player campaign.
When you reach any checkpoint throughout the game, drop the item on the ground that you want to duplicate. Kill yourself (Deo-Bombs, Molotov Cocktails, etc) and once the respawn timer begins to count down, pause the game and reload your checkpoint. When you respawn, everything you dropped on the ground will be back in your inventory, and will still be on the ground as well.
