There has to be a crossover on the Breath of the Wild Venn diagram between "people who really, really want all 900 Korok Seeds" and "people who don't mind cheating to get all 900 Korok Seeds", right? Good news for them: They can have their Korok cake and eat it, with this newly-discovered item duplication glitch!
The duplication glitch works for anything that can be stacked — star fragments, arrows, materials, food, and so on.
Here are the steps, as described by Gaming Reinvented:
- Go to any shop, including Beedle's travelling shop
- Drop the item you want to duplicate (or a whole stack if you want lots)
- Make sure you have no more of that item in your inventory
- Grab a multishot bow, and fire a shock arrow
- Drop the bow
- Repeat step 4 and 5, five or six times
- When Link starts to glitch out in the inventory (see image below), hold as many of a common item as you can
- Unpause the game
- If you've done it right, Link will be holding the items in the inventory, but not in the overworld
- Pick up the bows (so you can repeat the glitch)
- Speak to the shopkeeper and sell the common items you're "holding" in the inventory
- Pick up the item you want to duplicate
- Go to your inventory, and "stop holding" the common items
- This should replace them with copies of the duped item!
Time to be afraid, Koroks. We're about to steal all your seeds.