The Orb of Wishing

This might be one of the most fun magic items I have ever given to my players:

A larger crystal orb (1 Slot) that glows with strong inner light.

When you first touch the orb, you are flooded by strange visions that paralyse you until you succeed on a Will save. Once you pass, you gain control of the orb and may channel a sliver of its power - you have three wishes. It is not possible to wish alternatingly; once somebody else gains control of the orb, you lose any of your remaining wishes and may never again control the orb.

Zuran Orb from MtG

 

So far, the players have wished to:

1. Destroy the orb's guardian, averting a looming TPK.
2. Cure 50 years of unnatural ageing.
3. Regrow both hands of one unlucky companion.
4. Be cured of all ills. (Said character was severely injured and double-cursed.)
5. Become rich. (Wish pending completion, wait for the next session.)
6. Be young forever.
7. Grant human speech to their dog companion.
8. Resurrect a long-dead scientist for his lost knowledge.
9. Cure a fatal anaphylactic shock. (On the same character who had previously lost both of his hands...)

These wishes are in no way a monkey's paw. They follow the spirit of the request and sometimes even go a bit further, when the wording of the wish would needlessly weaken its beneficial effect. And yet my players are already paranoid, carefully planning on what to do with their effectively unlimited wishes. But are they truly unlimited? Who can they trust with the power of the orb, once everyone in the party has had their wishes granted? How can they compel anybody to wish for them? What if a word gets out? The schemes are piling up and up and up.

I must thank Skerples and Archon for the idea of giving the players a campaign-wrecking item early on and letting them loose. It is working gloriously.