I want to give my players a lot of dimensions and options to be clever.
I've already given the spellcaster a horrible device that I read about on reddit: A ring of the Grammarian (allows you to change one letter of a spell's name to change the effect). That was already interesting when he once cast "Firebaal" instead of Fireball.
I want to give each character a ring that's part of a multi-ring set. The general working idea is that it allows each player to "borrow" an ability from another. Not a race ability but a class ability. For example, the thief might be able to "steal" the wizard's "blink" spell. The ranger might be able to borrow the backstab ability from the thief. And the wizard might be able to borrow "pick lock" when he fizzles on a knock spell. And so on.
The idea isn't to give them power but to coordinate more during combat and tactical situations where the players must line up their actions to build to a crescendo action. Get them communicating and planning, really get into their character more.
Thoughts?
No, maybe not. A ring of protection is passive and requires no roll... but this could be considered an intelligent ring, right? I mean, it has to be. It has to communicate with the other rings who then has to delve into the mind of the person wearing it.
So the question is this: if it's intelligent, and perhaps too intelligent, it might have the capacity to control the user. Perhaps the intelligence should be just high enough to make that a risk but low enough to be enticing.