Forcecage and Summon Monster VII: possible error?

[Pleh]

I was looking at the CR 10 traps in the hypertext SRD and found this one.

http://www.d20srd.org/srd/traps.htm#cr10ForcecageandSummonMonsterVIItrap

It says this trap acts as two CR 8 traps combined: Forcecage and Summon Monster VII set to summon a Hamatula (a Barbed Devil). A CR 10 Trap summoning a CR 11 monster doesn't seem out of place to me (caging the person in a 10 to 20ft space with the creature seems a bit harsh), but as I was digging a bit deeper, I noticed that Barbed Devil requires a Summon Monster IX spell.

The trap reads that it is cast, "as a 13th level Wizard" which is just in range of a Summon Monster VII spell, but the greatest Devil summoned by that level of spell should be Bone Devil, not Barbed Devil.

What do you guys think? Did the game makers not know, not care, or did Hypertext SRD throw a typo in there?

[Eldariel]

In 3.0 SMVII was able to summon Barbed Devil but Summoning got later nerfed. They probably forgot to update the obscure combination example trap. 3.0 Summoning is mostly way better on high levels, though the differences are a bit erratic. As a rule, Demons suck; you get Quasit out of SMV and Vrocks are SMIX for example. At the same time at SMIX you have Astral Deva and Ghaele as 14TH LEVEL CASTING CLERIC (no Leonal though). No example list too so you presumably can access any Cleric spell of 7th level or lower with SMIX. But yeah. That's the reason.

[Pleh]

Ok, an old 3.0 carryover. That explains it. Thank you

[Thurbane]

Funny you mention this: I was looking through CR 8 traps for use against my ECL 8 party last night, and the DMG list included Prismatic Spray. This is a 7th level spell, which the party would normally only be encountering while going up against a 13th level caster. It seemed a bit much to me: especially since the results can include death or banishment to a random plane.

I used a 100 ft pit trap instead.

[Eldariel]

Trap CRs are kinda vindicated though; you can quite easily bypass them without ever having to "face" it. Triggering a trap is a fail condition so the effect has to be more powerful than the "automatic" condition caused by encountering an equal level caster who uses the spell no matter what you do, as opposed to when you fail to bypass/disable/solve the trap without triggering it.