How does calculate?

[SlashRunner]

How would one calculate the party's level for CR and the likes?
I've been going with (Sum of everyone's levels)/4, since 4 is what a party is "supposed" to be.

[erikun]

I generally take the average party level, +1 for every two people above the fourth. An increase in 2 CR is at least intended to be a double increase in difficulty, so a party of eight would be +2 CR compared to the average party. For lower levels (1st and 2nd) I would probably avoid anything larger than doubling the CR, though.

Your system would work for lower levels, but it would outright double a double-sized party. CR 6 shouldn't be too difficult for a 3rd level party, but CR 16 would likely maul an 8th level one.

[Mystral]

http://www.penpaperpixel.org/tools/d20encountercalculator.htm

This might be of use. It just calculates the party level the same way CR of more then one monster is calculated (Doubling of party members equals CR +2)

[SlashRunner]

How does calculate if not all the party members are the same level? My group has 3 players (might be adding a 4th sometime soon), but one of them has been missing for the last 3 sessions, so he's 2 levels behind the other players. By my method, that would make the average level of the party 3.33, considering that most D&D crap is based off a 4-person party.

[ericgrau]

It's supposed to be on page 48 of the DMG.

Roughly 2 equal level party members are equal to 1 party member who is 2 levels higher than them. So if you added up everyone's level that way and subtracted 4 (minus 2 twice, same as cutting a 4 man party in half twice to get the level of one person), that should give you a good estimate.

So if you had 2 level 5 guys and 1 level 3 guy that's like having 2.5 level 5 guys which is like 1.25 level 7 guys. So maybe that's a single 7.X ish guy which is equivalent to a level 3.X ish party. Maybe party level 3.5ish. The encounter calculator says 3.6 so I suppose this method isn't too far off.

[erikun]

How does calculate if not all the party members are the same level?
For "Party & Individual XP":
#2, ECL 4 (or whatever it is)
#1, ECL 2

This would give a party level of 2.6. It seems to work with different numbers of people in the party.

[EDIT]
How the heck does (x + y + z)/4 = 3.33 anyways?

[SlashRunner]

For "Party & Individual XP":
#2, ECL 4 (or whatever it is)
#1, ECL 2

This would give a party level of 2.6. It seems to work with different numbers of people in the party.

[EDIT]
How the heck does (x + y + z)/4 = 3.33 anyways?

Hmph. I think I might have accidentally divided by 3 instead of 4. Math fail on my part there.