Demon Summoning

[Vorput]

My character had an unfortunate run-in with a succubus last night, who was successfully able to summon a Vrock. Needless to say, I brought in a celestial bison, told him to protect me, and fled as fast as my little wizard legs could carry me.

Anyway, my question is how long does a Summoned demon last when a summon spell like ability brings it in? SRD quote:

Summon (Sp): Many demons share the ability to summon others of their kind (the success chance and type of demon summoned are noted in each monster description). Demons are often reluctant to use this power until in obvious peril or extreme circumstances.

Summon Demon (Sp)
Once per day a succubus can attempt to summon 1 vrock with a 30% chance of success. This ability is the equivalent of a 3rd-level spell.

If it's the equivalent of a 3rd level spell, does that assume minimum caster level (5th)- so 5 rounds? Since no caster level is listed though, and since a reluctance to use this ability seems to signify that it's a bit more than a summoned creature, is it actually a called creature?

Thanks in advance for the help.

Vorp

 

[Infiniti2000]

It lasts one hour.

Summon
A creature with the summon ability can summon specific other creatures of its kind much as though casting a summon monster spell, but it usually has only a limited chance of success (as specified in the creature’s entry). Roll d%: On a failure, no creature answers the summons. Summoned creatures automatically return whence they came after 1 hour. A creature that has just been summoned cannot use its own summon ability for 1 hour. Most creatures with the ability to summon do not use it lightly, since it leaves them beholden to the summoned creature. In general, they use it only when necessary to save their own lives. An appropriate spell level is given for each summoning ability for purposes of Concentration checks and attempts to dispel the summoned creature. No experience points are awarded for summoned monsters.

 

[Vorput]

Ah, missed that.... Thanks Infiniti.

Jeff

 

[Infiniti2000]

Ah, missed that.... Thanks Infiniti.

No problem.

The harder question, however, is how long it takes to summon the vrock. Does it take 1 full round "as though casting a summon monster spell" or does it take 1 standard action, the default for spell-like abilities unless otherwise specified?