Item decay allows you to have items decay over time, this is useful for things like food items going rotten.
You can set how long items take to decay and if they are replaced by another item after decaying like for example an apple item could become a rotten apple item. You can also have item be destroyed when the decay time ends. More info about this below.
The item decay effects items that are spawned or dropped in the world as well as items stored inside any inventory like the player or chest inventories. You can also set the Decay Multiplier in the any inventory components settings, this allows you to have storage that decays items at a fast or slower rate, so you could have storage like fridges that slow the speed of items decay. More info about this below.
Note – Item decay does not work with stackable items.
To find an item decay settings go to the ItemList and select and item row, in the Durability Details you will find the Decay Details open that up and you should see the settings shown below.
Here you can set it if the items decays, how long it takes to decay (in minutes), if the item should be destroyed when it decays and you can set the item that should replace it if thats something you want to happen.
To change the Decay Multiplier you can select any inventory component and in the details panel find the Decay Multiplier setting, for example you can go to the BP_WoodChest and select the BP_MasterInventory (Inherited) in the component panel, then in the details panel search for the Decay Multiplier setting like the image below.
If you set the Decay Multiplier to 1 item will decay at their normal rate, but if you set it higher like 2 item will decay at twice there normal speed, so an item that take 30 mins to decay will take 15 mins. If you were to set the Decay Multiplier to 0.5 items will decay at half there normal speed so an item that takes 30 mins would take 1 hour when stored in this inventory.
You can see how long an item has left before it decays in the item tooltip, just hover your mouse over the item when its in you inventory in game to see the decay time this time will change depending on the Decay Multiplier of the inventory its stored in. Remember that only item that have Use Item Decay set to true will have this information in there tooltip.