I came across this tweet from Gabe Hicks...
So immediately this is an incredible idea. I have always disliked the gems as material components idea for spells, and this is such a great way to fix it. This would explain why magical resurrection is rare, otherwise the rich would become essentially immortal. I love this. The question becomes: is it just the cleric casting the spell who sacrifices the HP, or could others join in? Here is my idea...
The hit dice of the character being resurrected are rolled, divided among any number of other characters however the players like. The target character returns to life with 1 HP, and their max HP is now equal to the total roll of the hit dice. Each character that participated in the spell loses max HP equal to what they rolled.
Give life to return life.
You could also do something fun like once they come back to life that character now rolls to see if they take on a personality trait of one of the characters who gave some of their life essence to bring them back. For 5E I would also give the resurrected character 3 levels of exhaustion and possibly 1 level of exhaustion to those participating in the spell.
