Cave state
Cave state refers to sneaking the dungeon ID ($040C) for caves 0xFF into areas of the underworld that are part of dungeons. There is a second cave state, 0xFD, obtained by using the throne room door while in the standard cave state.
Effects
Small keys
Every time Link enters a cave, the address that holds his current key count $00F36F will be set to -1, meaning "Don't show keys". In hexadecimal, this is 0xFF, or 255 as an unsigned value. Doors only check for 0 small keys, meaning that the dummy value of 0xFF will behave as 255 keys. Obtaining a key at 255 will overflow to 0 keys, preventing the use of this effect. Since the game doesn't track cave small keys and the value is set to 0xFF every time, small keys obtained in cave state are effectively lost.
Big keys
Big keys that work in cave states
When attempting to open a big chest or big key door or lock, the game's check will allow for one of several dungeon's big keys to pass.
| Dungeon ID |
Dungeon big key | |||||||||||||
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| Hyrule castle | Sewers | EP | DP | ToH | Aga | PoD | SP | SW | TT | IP | MM | TR | GT | |
0xFF
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0xFD
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Big keys that get set in cave states
When grabbing a key in cave state, multiple dungeons' big keys will be marked as obtained.
| Dungeon ID |
Dungeon big key marked | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Hyrule castle | Sewers | EP | DP | ToH | Aga | PoD | SP | SW | TT | IP | MM | TR | GT | |
0xFF
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0xFD
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Mirror usage
The mirror cannot be used in the standard cave state, but it can be used in the throne roomed cave state. Doing so will return Link to the original entrance he came in, as if it were a dungeon.
