When does the -3 STR penalty from using wish wear off?

Question

AD&D 2nd edition's version of wish has several drawbacks:

[...] All wishes age the caster 5 years. Stronger wishes impose a -3 penalty on Strength on the caster and require 2d4 days of bed rest for the caster due to the stresses the spell places on time, space, and the body.

When does the -3 STR penalty from using wish wear off?

Answer 1

Having scanned the DMG, the PHB, and the Complete Wizard's handbook, the rules don't specify. As with most things involving wish, the DM needs to make a ruling. Beyond what you cited from the PHB, in the Complete Wizard's Handbook (p. 125) says:

Since it can theoretically have any effect, no spell is more difficult for the DM to adjudicate than wish. {snip} DM is free to alter these suggestions in any way he sees fit. {snip} The nature of the penalty is up to the DM; possibilities include 2d4 days of bed rest, a temporary loss of 1-4 Strength points, a permanent loss of 1 Constitution point, damage of 2d10 points, or any combination of these penalties.

It would make sense for the loss of Strength points to last as long as the need for bed rest, 2d4 days, but the DM can adjust that to fit a particular situation.

Dungeon Master Option: High Level Campaigns duration = bed rest time

If you accept players option series of books(sometimes referred to as AD&D 2.5) the Dungeon Master Option: High Level Campaigns(p. 93) offers this guidance:

Wish: Most uses of this spell lower the caster's Strength/Stamina score by three points, and force the caster to take to his bed for 2d4 days. Lost Strength / Stamina return at the end of the rest period. If the caster's Strength score falls to 0 or less, he loses consciousness until he has rested.

(While I don't recall a Dragon Magazine Sage Advice article on this, there may be one ... that may take a while to dig up. Dragon Mag #146 had a great article on wishes that referred to D&D/BECMI, AD&D 1e and covered other RPG's as well. It had no treatment of the price/penalty of using wishes in a game).