Adjusting EL for NPC allies?

[Drakevarg]

How does one adjust the CR for an encounter when the PCs have NPCs on their side? I'd go more into the overall concept itself, but I'm guessing most already understand what I'm talking about and I'm too tired to get too much into game theory just now.

Here's the scenario in question:

PCs:
Elf Druid 5
Elf Monk 5
Human Dread Necro 5
Dwarf Cleric 5
Celestial Elf Rogue 3

NPCs:
20 Human Swashbuckler 1s
5 Human Swashbuckler 3s
Human Swashbuckler 5

What would an appropriate CR be against this group? Right now I'm guessing somewhere in the neighborhood of 11, but I'd rather not discover I'm wrong by way of a 3-round TPK.

[Dumbledore lives]

I couldn't give you an exact CR, but the lvl 1s are going to do little to nothing, the level 3s will do a bit more, but still little, especially as swashbucklers. Account for the level 5 in your CR, and maybe bump it up by one more for the rest of them, a CR 11 would destroy them, very quickly. I'd say 6, maybe 7 for a typical encounter, but even that is pushing it if you have 4.

[crazyhedgewizrd]

I will agree with 6/7 for the CR of encounters, but as soon as the 20 lvl 1's die drop the CR down to 5/6.

[Drakevarg]

Don't suppose there's a formula of some sort to determine these things? I prefer eyeballing only as a fine-tuning technique, but having math on my side allows to be to come up with the base concepts quickly.

I came up with CR 11 because that was my estimate of the CR rating of the ship's crew (on the basis of the rule that two encounters of the CR = CR+2). So:

2 Deck Hands (Level 1s) = CR 3
4 Deck Hands = CR 5
8 Deck Hands = CR 7
16 Deck Hands = CR 9

2 Sailors (Level 3s) = CR 5
4 Sailors = CR 7

So, 16 Deck Hands (CR 9) + 4 Deck Hands (CR 5) + 4 Sailors (CR 7) + 1 Sailor (CR 3) + 1 Captain (Level 5s) (CR 5)

4 Deck Hands + 1 Sailor = CR 6
4 Sailors + 1 Captain = CR 8
CR 6 + CR 8 = CR 9
CR 9 + CR 9 = CR 11, which accounts for the whole crew.

I know there's a point where the lower levels just stop being relevant, but I'm not sure where that is except in the sense that it takes exponentially higher numbers of them to matter (in the Azure City battle sense).

[Ernir]

This is discussed on page 48 of the DMG, and the next few pages after that. Use this. (http://www.d20srd.org/extras/d20encountercalculator/) Remember that these guidelines can be inaccurate to the point where CR eyeballing is an essential tool for a 3.5 DM.

[Siosilvar]

CR11 might be the CR for the entire crew, but remember that a party of 4 PCs has a CR 4 higher than their level and is still only expected to go up against CRs equal to their level on average. Not to mention that 16xCR1 is not worth CR9, since a CR9 challenge will be able to hit and kill at least two of them per round, while they'll be stuck waiting for a natural 20.

[Drakevarg]

Well the calculator told me exactly what I expected for the CRs itself, but I'm not quite sure how Party Level is calculated, as the party + the NPCs came out to 8.2.

[Canarr]

Personally, I'd recommend letting the PCs and their allies fight separate enemies.

I'm assuming there'll be ship to ship combat, boarding actions, and the like? Then have the PCs' crew fight the enemy crew (with the option of letting any PC with command inclinations influence their crew's performance) and place a few higher level enemies for the PCs to fight. Problem solved.

Otherwise, once the PCs start going up against CR 6, 7, 8... enemies, their low-level retainers are toast.

[DeAnno]

Are the lives of the 20 Swash 1's important? If they are, you could have an "easy" battle where the principal difficulty is babysitting them. Otherwise they will die in droves.

[Doug Lampert]

How does one adjust the CR for an encounter when the PCs have NPCs on their side? I'd go more into the overall concept itself, but I'm guessing most already understand what I'm talking about and I'm too tired to get too much into game theory just now.

Here's the scenario in question:

PCs:
Elf Druid 5
Elf Monk 5
Human Dread Necro 5
Dwarf Cleric 5
Celestial Elf Rogue 3

NPCs:
20 Human Swashbuckler 1s
5 Human Swashbuckler 3s
Human Swashbuckler 5

What would an appropriate CR be against this group? Right now I'm guessing somewhere in the neighborhood of 11, but I'd rather not discover I'm wrong by way of a 3-round TPK.


Don't suppose there's a formula of some sort to determine these things? I prefer eyeballing only as a fine-tuning technique, but having math on my side allows to be to come up with the base concepts quickly.

For creatures of less than CR 11 or so you can simply use the XP table for characters of level 1-3, add together all the XP values they're worth and then divide by 4, that's about the EL of an "appropriate" challenge. There's some round-off problems, but that gives a reasonable approximation.

Thus 4 level 5 characters should face a EL 5 encounter.

You have 5 ECL 5 characters, worth 1800 each, 20 level 1 NPCs, worth 300 each, 5 level 3 NPCs, worth 900 each, 1 level 5 NPC, worth 1800.

So a set of hypothetical low level foes would get 21,300 XP from fighting this gang. Which means they should be facing something worth 5,425 XP, which is between EL 8 and 9 (which is what the web-tool told you).

But there's more to encounter design than EL. The problem is that a single CR 8 monster will rip through the level 1s and unless they're ranged they'll be unable to bring their numbers to bear, so you need to use a mob of lower level threats, not a single CR8.

This is the same reason that for more than a dozen monsters you should consider counting only the 12 or so strongest monsters in determining EL. It's simply too hard for masses of low levels to bring their numbers to bear effectively.

You need to either use a mob of comparably low level foes or count only the dozen or so most dangerous characters. Which drops this to only 15,600 XP.
Which suggests that the foe should be worth about 3,900 XP, or EL 7.

So a single EL 7 monster or small group of monsters or a mob of at least 10 or so monsters who combine to EL 8 where the low levels will have foes they can fight.

Note that a "standard" encounter has an EL four less than the party would were the party monsters. This is because the party is expected to WIN "standard" encounters with reasonable ease (aka 20-25% consumables expended), and for the group you describe the level 1 NPCs probably count as consumables, 20% of 20 NPCs is 4 dead guys, expect to lose some almost every fight.