Vital Exchange

You sacrifice a portion of your own life essence to heal another. When you cast this spell, choose how much necrotic damage to take from the following options:

• Roll 1d8 necrotic damage

• Roll 2d8 necrotic damage

• Roll 3d8 necrotic damage

• Roll 4d8 necrotic damage

You take the chosen damage, which cannot be reduced in any way. One creature you can see within range regains hit points equal to twice the necrotic damage you took.

Using a Higher-Level Spell Slot. When you cast this spell using a spell slot of 3rd level or higher, the damage increases by 1d8 for each slot level above 3rd and you can heal an additional creature which receives half the healing amount of the previous target  rounded down.