Spell traps

[AlphaBond102]

I've noticed a lot of stuff about spell defense traps (traps that catch spells and stuff), so I was thinking... Why not simple spell traps? I'm saying traps that you fill with a spell you made ( So you make a lightning spell and instead of taking it to battle you fill a trap). This would be an effective yet expensive trap to wipe out enemies. This can also allow more types of spells to be made (Anti giant traps for example). The trap itself would not need to be rearmed but will need to be refilled after use. Please build off of this This idea may have already been mentioned but I think it should be a little relevant.