A beam of amber earthen energy lances out from your finger at one creature that you can see within range. Make a ranged spell attack against the target. On a hit, it takes 5d10 necrotic damage, and it must make a Constitution saving throw if it has any limbs. On a failed saving throw, you choose one of its limbs to affect. That limb is turned to stone until the spell ends, and cannot be used to make attacks. The effect of losing a limb can be found in the following table, based on the chosen limb:
Affected Limb | Effects of Petrification |
Arm | The target can no longer hold anything with the affected arm. If it only has one functional arm remaining, it can't hold anything with two hands, and it can hold only a single object at a time. If no arms remain, it can't hold anything at all. |
Leg | The target's speed on foot is halved. If half or more of its legs are not functional and not replaced by prostheses, it must use a cane or crutch to move, it falls prone after using the Dash action, and it has disadvantage on Dexterity checks made to balance. If no legs remain, it can't walk at all, and must crawl. |
Wing | The target's flying speed is halved. If half or more of its wings are not functional and not replaced by prostheses, it cannot fly without the aid of magic. |
Tail | The target's swimming and climbing speeds are halved, except those granted by magic, unless the limb is replaced by a prosthesis. |
Fin | The target's swimming speed is halved unless it is granted by magic or the limb is replaced by a prosthesis. |
For the duration, the target must make another Constitution saving throw at the end of each of its turns. If it successfully saves against this spell two times, the spell ends. If it fails saves four times, it stops making saving throws for this spell. The successes and failures don’t need to be consecutive; keep track of both until the target collects enough of either kind.
If you maintain your concentration on this spell for the entire possible duration, the limb stays petrified until the effect is dispelled or removed. Any effect that can end the petrified condition or restore a missing limb can also end this effect. If the affected limb is physically broken while petrified, it suffers from similar deformities if it reverts to its original state.
Undead, constructs, and creatures that cannot be petrified are entirely immune to this spell.
At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the damage dealt increases by 1d10 for each slot level above 3rd.
* - (petrified bone or amber worth at least 75gp)
I hope it isn’t too rude to say, but I think the damage for a spell that already has the potential to cause a permanent crippling effect is maybe too high.
Maybe reduce it to 2d10 or 4d6?
Though the number of saves required to make it permanent vs end it likely balance it out