The spell Wish states:
You might be able to achieve something beyond the scope of the above examples. State your wish to the DM as precisely as possible. The DM has great latitude in ruling what occurs in such an instance, the greater the wish, the greater the likelihood that something goes wrong. This spell might simply fail, the effect you desire might only be partly achieved, or you might suffer some unforeseen consequence as a result of how you worded the wish.
And:
The stress of casting this spell to produce any effect other than duplicating another spell weakens you. […] Finally, there is a 33 percent chance that you are unable to cast wish ever again if you suffer this stress.
If Wish fails due to the highlighted clause in the spell, does the caster suffer stress, and thus risk never being able to cast the spell again?
Best Answer
Yes
The spell casting didn't fail, the wish (PHB, 288) you requested (assuming it isn't a spell duplication) failed to be granted. That's the big difference. You successfully cast wish, but it was did not successfully resolve for you (for whatever reason.)
The spell clearly states (emphasis mine):
If you attempt a wish that isn't a spell duplication, then you put yourself at risk because you are now under stress.