Discern Lies Used to Force Concentration Checks

[resistingfanatic]

A friend and I were discussing this recently and for obvious reasons it seems overpowered and/or broken. This trick revolves around the 5th level Inquisitor Class ability called Discern Lies, cast as an immediate action.

Firstly, the spell discern lies does in-fact target creatures you use it on. They get a save to resist the effects, and as long as the concentration is maintained, it should be a dispellable effect. Provided said creature(s) fails the save, it is then considered to be "affected by a non-damaging spell" if it were to cast, forcing it to make that Concentration Check. The clarification I'm interested in is in using the spell on a spellcaster when they cast a spell in order to provide another barrier to success.

a flow chart:
spellcaster begins casting-->inquisitor uses an immediate action to cast discern lies-->spellcaster fails save and is affected-->spellcaster is forced to make a concentration check

Everything I've been able to find on the subject seems to point toward it being legitimate, but this would be a very large abuse to the spirit of the ability. Please shed some light on this dilemma. : )

[Russ Taylor]

It doesn't seem to meet the other requirements of a concentration check. From the PRD:

Quote:

If the spell interferes with you or distracts you in some other way, the DC is the spell's saving throw DC + the level of the spell you're casting. For a spell with no saving throw, it's the DC that the spell's saving throw would have if a save were allowed (10 + spell level + caster's ability score).

Detect lies wouldn't interfere with or distract from spellcasting, since no lying is involved.

[Jeraa]

Discern Lies does not interfere or distract you in any way, so no concentration check is needed. Someone taking a ready action to cast say, Sleep, could require a concentration check. Assuming you made the save anyway. But not likely, as the spell isn't actually affecting you... I'll try to find a better example.

Edit: A Slow spell maybe? Cause Fear could possibly require a check, as could Lullaby. Ray of Enfeeblement applies a penalty, but doesn't do damage. It too could require a check. I could also see any spell that makes you Blind or Deaf causing you to make a check as well. As could possibly Enervation and Energy Drain.

[Magicdealer]

I see where you're getting your interpretation from.

Page 206 on Concentration checks lists the following subcategories: Injury, Spell, Grappling or Pinned, Vigorous Motion, Violent Motion.

Under Spell, it says:
"If you are affected by a spell while attempting to cast a spell of your own, you must make a concentration check or lose the spell your are casting. If the spell affecting you deals damage, the DC is 10 + the damage taken + the level of the spell you're casting.
If the spell interferes with you or distracts you in some other way, the DC is the spell's saving throw DC + the level of the spell your casting."

The first sentence there can be misleading if you don't follow to the specifics. But the spell being cast on you must "interfere with you or distract you in some other way".

The Discern Lies class ability doesn't have any effect on the target. All its properties involve bringing information to the caster. Since this effect doesn't interfere with the target, or distract the target, it doesn't force a save.