The ally summoning ability of demons and devils.

[Land Outcast]

Simply put, if a CR6 creature is CR6 because it can summon another CR6 creature, what CR should he be if I remove the his summoning ability?

Excellent question

 

[CRGreathouse]

Can't be. Take the Babau for instance. That's a good solid CR 6 creature (7 HD, some great immunities and defensive abilities, and +2d6 sneak attack). A nice challenge for a party of 4 6th level characters. But, he has a 40% chance of summoning ANOTHER CR 6 Babau. Suddenly, the PCs are in pretty deep.

That's two CR 6 creatures, and it remains an ECL 6 encounter. That's not right.

A lone babau is weak for a CR 6; it's glass-jawed. Possibilities for combat:

• The babau chooses not to summon another babau. It's slightly weak for its CR.
• The babau tries to summon another of its kind, but fails the DC 18 check (60% chance) to use it defensively. It's weak because it wasted a round.
• The babau tries to summon another of its kind, but doesn't do it defensively and is disrupted. It's weak because it wasted a round and was damaged.
• The babau tries to summon another of its kind, but fails (60% chance). It's weak because it wasted a round.
• The babau tries to summon another of its kind, passes the spell-like ability defensively check (40% chance)/avoids the AoO/is out of melee range/passes the disruption Concentration check (< 65% chance) and also succeeds on the summon (40% chance). It's strong for its CR, since the round is well-used.

If you're arguing that the actual difficulty is variable, I agree. If you're arguing that the babau is too strong because of the possibility of the final situation, I don't agree -- in all other situations it's weaker than EL 6, in some cases significantly. The last scenario (one damaged babau and one fresh babau) is probably EL 7; the others are in my estimation from EL 4 to EL 5.5.

 

[CRGreathouse]

Simply put, if a CR6 creature is CR6 because it can summon another CR6 creature, what CR should he be if I remove the his summoning ability?

That's a good question. If a CR x creature can summon another CR x creature 1/day as a free action without provoking AoOs and without chance of failure, then it would be CR x-2 without the summoning ability*. If the summon chance is y%, but the other conditions hold, then the CR without summoning would be x-y/50.

A CR 6 which could summon another CR 6 1/day as a free action without provoking AoOs and with a 40% chance of success would be CR 6 - 40/50 = CR 5.2. The babau, if properly CR'd, has a CR between 5.2 and 6 without the summoning ability, since it isn't a free action and does provoke AoOs.

* Actually, this doesn't hold for small CRs. CRs 4 and below should be halved, instead.

 

[Stalker0]

There are a lot of creatures in dnd that have high variability, and so combat can greatly shift one way or the other.

Look at some poisons, there are ones that do 1d8 con damage. You roll a 1, no big deal, fight goes on. Roll an 8, and your party may have just lost a member. This is part of the excitement of combat, the uncertainty.

 

[Khementari]

Summoning is part of a demon or devil's CR. You don't get more encounter xp for fighting another CR. Fighting things like that is and should be a horrible experience.

 

[Tequila Sunrise]

Hmm well it seems that I'm in the minority again; I've always given double xp for a babau that summons one of its buddies.

 

[CRGreathouse]

Hmm well it seems that I'm in the minority again; I've always given double xp for a babau that summons one of its buddies.

That's fine, as long as it's with your eyes open. If you realize that the DMG says specifically not to give more XP when fighting a creature summoned by another, and that the MM CRs are balanced with that assumption, do whatever you like as DM. Certainly, I can see the social arguments for it.