IST Simulator

The IST (Inventory Slot Transfer) is the most complex data manipulation glitch in Breath of the Wild. Discovered in June 2022, it quickly became apparent that external tools were needed to plan and execute it without tearing your hair out. That's where the IST Simulator comes in.

What is the IST Simulator used for?

Attempting IST blindly requires mentally tracking the state of the game's memory every single time Link picks up or drops an item. The slightest mistake can ruin your save file. The simulator's purpose is to automate this entire process:

• Step-by-step planning: You input your actions using simple commands (e.g., get 1 apple, drop weapon), and the tool displays the exact memory state of your inventory in real-time.
• Routing and Correction: If you change a single action in the middle of your sequence, the simulator instantly recalculates the impact on all subsequent steps. This is crucial for creating optimal speedrun routes.
• Support for complex corruptions: The tool flawlessly handles the most advanced mechanics, such as Weapon Modifier Corruption (WMC) or Direct Inventory Corruption.
• Absolute precision: Skybook's engine is so faithful to the actual game that it can even validate setups that players initially thought were impossible.

In short: the IST Simulator handles all the heavy mathematical and memory calculations for you, allowing you to focus purely on the in-game execution.

Useful Links

IST Simulator — The web app to create, test, and share your setups.

Manual and Documentation (Skybook) — The official documentation to understand exactly how the tool and the glitch work.