You know, I'll have to talk to him more about it on Friday. I was thinking about his character and he has +13 to Arcana and +11 to Nature due to Expertise in both skills (he is a Bard). I sort of like the idea of adding half his caster level (round down) to his checks. So, for really high DCs (25+) the bonus will help but not make it guaranteed. I don't know, but it is an idea.If the player is not trying to min-max by using the spell as a substitute for arcana/nature/etc, then you might consider a spell along the lines of 3e's find traps and letting her add half her caster level to the roll. Or if the player is trying to min-max by using the spell as a substitute for arcana/nature/etc, then you might consider a spell along the lines of 5e's find traps that would automatically confirm the presence of an anomaly but wouldn't provide detailed information about exactly what the anomaly is. That would make the spell simultaneously more and less powerful than arcana/nature/etc without being a complete substitute for them, and might not even require a consumable material component for balance.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.