The idea here is to add a curse system to equipment and weapons (it's inspired from Pixel Dungeon, a little RPG).
Mechanic
A cursed item isn't movable from equipment slot if you equip it, and it has a bad bonus (like -10% of accuracy for a weapon, and less defense for armors (it will be writed in red)...).
New items
This system includes new items : a scroll of curse removing (remove a curse on an item), and an identify scroll (identify if item is cursed). The first one is cheap (very), and the second one is not.
Chance to get a cursed item
The chance of getting a cursed item is high if you get it from a dungeon or a monster, low for merchants. For market, you can sell a cursed item (but its less cheap), an uncursed item will be cheaper.
Description of cursed/uncursed item
When you read item description, it will be writed "???" (don't know if item is cursed), "cursed" (if item is cursed) and nothing if item have no curse.
Exemples of curses
The basics : less accuracy, defense, attack...
Others : can't add runes or crystals on item, low chance to get randomly teleported (on weapons only)...
Horrible : unable to use a skill, less chance to get good stuff...
I think you have many ideas to purpose...
Hope you enjoyed read this !
Imagine it get realised !!!