About not being able to use certain wagered item, you could still accept the wager just like if they wagered a burrito. Even if you can't use it then it still might be very useful in your possession so that they [i]can't[/i] use it. However, the other person should make it clear when wagered that this is the case. No saying, "Oh yeah, you can't use this" after you already lose it in a wager.