In order to get your hands on Oil In Graveyard Keeper you can do one of two things, either buy it or make it yourself.
To buy Oil, head East alongside the dirt path outside of the Dead Horse Tavern in the Village until you come across a bunch of old stone ruins. Among these ruins should be an NPC named Dig, one of the three Seed Vendors in the game.
You can either buy Seed Oil directly from Dig, or you can buy Hemp Seeds from him, which can then manually be converted into Seed Oil. I recommend buying Hemp Seeds to save a bit of money.
Now go into the Farming and Nature tab in your skill tree and unlock the Winemaking skill to get access to the Vine Press blueprint, and then build it in your home’s Cellar.
You can now use 4 Hemp Seeds to make one bottle of Seed Oil each and every time. Alternatively, you can use 5 pieces of human fat, harvested from corpses, to make oil.
One thing that might confuse players at this stage is that you cannot use the oil in it’s current bottled form. In order to make use of it, go into your inventory and use the Seed Oil to get 10 units of Oil, which is different to the bottle of Seed Oil.
This is sort of similar to how you need to use a Bucket of clear water in your inventory to get 10 units of water for Baking Bread.
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