EL for NPCs

[Razanir]

For an (eventual) adventure, I'm making evil versions of the PCs to fight. I'm just wondering EL-wise, do 4 10th level NPCs count as 3 CR 10 monsters, or as EL 10 altogether because they're a party of 4 level 10s?

[Urpriest]

NPCs with core races have CRs equal to their level, so four level 10 NPCs is an EL 14 encounter. A boss battle, basically.

[Jeraa]

A single CR 10 creature is supposed to make a 10th level party use roughly 20-25% of their resources. 4 CR 10 creatures would use between 80-100% of a parties resources. A couple unlucky dice rolls, and you've got a party wipe. You basically giving the party their entire days worth of encounters at one time.

(Encounter-level wise, 4 creatures have an EL equal to their individual challange rating +4. 4 CR 10 creatures are a 14th level encounter. You can find the encounter level chart on page 49 of the DMG.)

[Runestar]

Are your npcs outfitted according to npc wealth limits?

On paper yes, that is a EL14 challenge. However, I find that classed npcs are rarely ever worth their cr (they are often statistically weaker than monsters of the same cr), and this disparity grows even larger at higher lv games.

As a general rule of thumb, I would peg melee npcs at 2/3 their class lv, and spellcasters at -1cr (either that or use the non-associated class rule to compensate for their fragility). So a 10th lv human fighter would be cr6-7 (with wealth appropriate for a cr6-7 npc). Outfitted this way, your 10th lv party would work out to be a EL11-12 challenge.

Fighter10 -> cr7
Rogue -> cr7
Wizard10 -> cr9
Cleric10 -> cr9

[Razanir]

If it helps, the sides are (by the way, it's gestalt):
PCs
A Mind Flayer//Wizard (Savage Species)
An Aasimar Cleric//Monk
A Human Fighter//Ranger

NPCs
A Tiefling Barbarian 10//Druid 10
A Half-Elf Summoner 10//Sorcerer 10 (Summoner borrowed from PF. We're mostly 3.5)
A Half-Elf Bard//Scout (Complete Adventurer)
The summoner's Eidolon (8 HD)

[Urpriest]

The Eidolon doesn't count for EL, nor does it give XP. You've got three level 10 NPCs.

Here's a worked calculation to show you how it's done:

EL is additive, but it adds in a weird way. Let's start with the Tiefling and Summoner. Both are CR 10, so together they're EL 10+2=12.

Now we add the Bard. The Bard's CR is 10, 2 under the EL of the others combined. This makes them a mixed pair, which is worth 1 EL more than the highest EL in the pair. You end up with EL 12+1=13.

Note that in gestalt none of this applies, and you're supposed to homebrew challenges and XP based on what you think gestalt does to the power level.

[SleepyShadow]

Is Team Evil supposed to survive and escape to fight another day? If so, you may consider giving them PC wealth rather than NPC wealth.