OoT - Why some items get written to unusual slots

When you receive an item, the game checks which type of item it is.

-If it's a quest item, the game will update the quest item data in your save file
-If it's a piece of equipment, it will update the equipment data in your save file.
-If it's a bottled item, it will attempt to fill an empty bottle, and if you dont have one, it will place it in the first bottle slot.
-If it's something like a magic jar, heart piece, or ammo refill, it will update that data.

-If it's none of the above, it will attempt to write it to an inventory slot. This is what the game uses to write most items such as hookshot or deku nuts in your inventory. It uses the following table to determine where to place an item:

https://i.imgur.com/k8LhYRu.png

The item slot table is the white data and the other colors are for unrelated data. The item slot table consists of 60 values which are used for items 0-59 (except for things like quest items, equipment upgrade, bottled item, etc.). For example, the first white square is 0, which signifies that item 0 (deku stick) will be placed in slot 0 (deku stick slot). Item values 7 and 8 (Fairy Ocarina and Ocarina of Time) both go to slot 7 (ocarina slot), so there are two 7's in a row later on that line.

When you receive a glitched item (an item larger than 59 which is not a quest item/equipment/item refill/bottled item/etc.), it will use the data after the table as the slot. For example, item #200 (https://www.youtube.com/watch?v=EOwnhs1yrwg) gets placed in a slot determined by the entry 200 on that chart, which ends up being a 0, which is the Deku stick slot. That's why received glitched items can go into weird slots, and can overwrite things like flags (shown here https://docs.google.com/spreadsheets/d/1SLJzamokLb7wDOaJh5x8DsxmMBy9oIYawyDN3dAWppw/edit?usp=drivesdk)

Bomb bag 20 is a special case. It is an equipment upgrade, so normally it gets written to the Bomb Bag slot on the equipment screen. However, if you already have something in that Bomb Bag slot, it looks at the slot table for the entry 77 (because Bomb Bag 20 is item #77) and finds an 8. It places the Bomb Bag in slot 8, which is the bombchu slot.

The same thing happens with Quiver 30, if you obtain it while already having a Quiver: https://www.youtube.com/watch?v=MYr5tfyKKic