Nondetection spell-like ability DC?

[Alzrius]

A point recently came up in a conversation I was having with someone, and I wanted to get some input.

Spell-like abilities always set their DC as 10 + spell level + Cha modifier. Easy enough. However, the nondetection spell has a clause that says:

If you cast nondetection on yourself or on an item currently in your possession, the DC is 15 + your caster level.

So then, if a monster with nondetection as a spell-like ability uses it on itself, does it follow the method prescribed above (15 + CL) or does it use the standard formula of 10 + spell level + Cha modifier?

 

[StreamOfTheSky]

I would say yes, 15 + CL, but I have no rules source to cite. It's not a save DC, as the typical formula is for, though. It's a DC for a CL check, so I think it's appropriate that it doesn't follow the save DC formula.

 

[NewJeffCT]

I would think the DC for spell-like abilities would take precedence, as it would (hopefully) note that in a monster's description if it differed from the norm.

 

[Voadam]

From the srd

The saving throw (if any) against a spell-like ability is:

10 + the level of the spell the ability resembles or duplicates + the creature’s Cha modifier.

Nondetection has a save of will negates harmless. The spell like ability applies to that save only. Nondetection gives a special power imposing a caster level check defense with a specific non save DC upon the affected target.