Wish

Wish is the mightiest spell a mortal creature can cast. By simply speaking aloud, the caster can alter the very foundations of reality in accord with their desires. The basic use of this spell is to duplicate any other spell of 8th level or lower. The caster need not meet any requirements in that spell, including costly components. The spell simply takes effect.
Alternatively, the caster can create one of the following effects of their choice:

• The caster creates one object of up to the value of twenty five thousand gold that isn't a magic item. The object can be no more than three hundred feet in any dimension, and it appears in an unoccupied space the caster sees on the ground.
• The caster allows up to twenty creatures that they can see to regain all hit points, and they end all effects on them described in the Greater Restoration spell.
• The caster grants up to ten creatures that they can see resistance to a damage type they choose.
• The caster grants up to ten creatures they can see immunity to a single spell or other magical effect for 8 hours. For instance, the caster could make themselves and all their companions immune to a Lich's life drain attack.
• The caster undoes a single recent event by forcing a reroll of any roll made within the last round (including their last turn). Reality reshapes itself to accommodate the new result. For example, a wish spell could undo an opponent's successful save, a foe's critical hit, or a friend's failed save. The caster can force the reroll to be made with advantage or disadvantage, and they can choose whether to use the reroll or the original roll.

It is possible for caster to be able to achieve something beyond the scope of the above examples. In that event, the caster states their wish as precisely as possible. The greater the wish, the greater the likelihood that something goes wrong. This spell might simply fail, the effect the caster desires might only be partly achieved, or the caster might suffer some unforeseen consequence as a result of how they worded the wish. 
For example, wishing that an enemy were dead might propel the caster forward in time to a period when that villain is no longer alive, effectively removing them from their life. Similarly, wishing for a legendary magic item or artifact might instantly transport the caster to the presence of the item's current owner.
The stress of casting this spell to produce any effect other than duplicating another spell weakens the caster. After enduring that stress, each time they cast a spell until they finish a long rest, they take 1d10 necrotic damage per level of that spell. This damage can't be reduced or prevented in any way. In addition, the caster's Strength drops to 3, if it isn't 3 or lower already, for 2d4 days. For each of those days that the caster spends resting and doing nothing more than light activity, their remaining recovery time decreases by 2 days. Finally, there is a 33 percent chance that the caster is unable to cast wish ever again if they suffer this stress.

Related School

Conjuration

Effect Duration

Instantaneous

Effect Casting Time

1 Action

Range

Self

Level

9th