Sharing time!
So, one of my players chose the wrong door out of the land of the dead, deciding to go where the object of his selfish desire (a sword) was unattended, rather than the path of the selfless hero.
I am about to drop him in the room, with moments to grab it before anyone comes back for it…until his hand goes straight through it.
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You are a Ghost.
You are a ghost in the waking world, kept in existence either to serve or amuse Death. You retain your stats, but zero HP, no gear, and no corporeal form. You are unseen and unheard.
To wreak violence, roll+STR. Your damage may only be d4, but it is forceful and ignores armour.
To move an object, roll+DEX.
To remember your life, roll+INT.
To impose your will, roll+WIS. This can be used to possess an unconscious body who then becomes a volatile Ghoul or Vampire. This undead host starts with 1d6 hold, and must consume flesh or blood to gain hold (2d6 per murdered adult humanoid) to spend per move. When the hold reaches zero, it falls apart.
To become momentarily visible, roll+CHA.
You may spend your Charisma, one point per roll, to promote a failed roll to a partial success, or a partial success to a full success.
When your Charisma is spent, your spectre fades to nothing at all.