Wishes

Wishes are a key part of adventuring, and are not restricted to those capable of casting limited wish, wish, or alter reality directly. Wishes can be obtained from a number of sources, including multiple magic items and monsters. When making a wish, it’s important to word the wish very carefully, as wishes will be taken in the most literal sense, and some wish-granters (like efreeti) will try to twist the wording of the wish as best they can.

Safe wishes

The following are considered “safe wishes,” meaning they can be expected to take their intended meaning without twisting (exception: efreeti and other evil entities will often attempt to twist even these):Ex1)

Using wishes to surpass level caps

Wishes cannot be used to surpass class level caps, regardless of whether the cap is due to the nature of race or the limits of the class.3)

1)
These are a selection of pretty “standard” wishes in AD&D, taken from and extrapolated from various sources, including the core rulebooks. Making these wishes safe from twisting is not an official game rule, though. DMs are free to be as wish-hostile as they'd like their campaign to be. That being said, wishes are rare, and many DMs make them even more rare by not properly placing all rolled magic items when generating treasure. We recommend DMs not be afraid to place wishes at any level of gameplay, and to provide a selection of safe wishes like these so players can understand what is reasonable. In that way, they can gauge things, and when they inevitably want something not on this list, they will need to choose between a safe wish, or something they really want. It's at that point that DMs can get really creative with fulfilling the wish. Not to say there isn't plenty of room for creativity fulfilling these safe wishes.
2)
DMG 11. Remember to note that increases past 16 only increase a tenth of a point per wish.
3)
Allowing this would probably make it the “best” use of a wish. A party would likely often want to save their wishes to use on breaking level limits. Socially, players of non-humans may even go so far as to expect that the wishes will be used on their characters, since gaining an extra level can be so powerful for the party. Furthermore, the other major power increases that can be gained from wishes are more restrictive. Ability scores past 16 require 10 wishes per single point, and wishing for a magic item only gives the location of such a treasure. All that being considered, we do not recommend that wishes can be used in this way.