Anyway, this is just part of my recent musing on "counterspells" in (A)D&D.
Level: Magic-User 3
Duration: 1d3 rounds +1 round/two caster levels (round down)
Area of Effect: One spellcasting creature
Components: V, S, M
Casting Time: 3 segments
Saving Throw: Negates
The target of this spell must be a single spellcasting creature. "Spellcasting" in this case means that the target casts pre-memorized spells in the fashion of a cleric, magic-user, or other regular PC class. Innate spell-like abilities alone are not sufficient, nor is magic item use, and neither of these functions are impaired in any way by Spellcheck. If the initial saving throw versus spells fails, the target must roll another save versus spells each time spellcasting is attempted during the duration of Spellcheck. Failure indicates that the spell in question is not successfully cast and is instead expended without effect. This spell's suggested material component is an iron padlock, which can be any size (even downright miniature), so long as its design and workmship permits it to function. This item is consumed utterly upon casting of the spell.