Calculating effective party level

[thorian]

When trying to determine an appropriate encounter level for a party, the formula for the effective party level is fairly simple if there are 4 characters -- you take the average of the 4 character's levels and determine the effective party level. How is the formula different for parties that are not comprised of 4 characters?

 

[Jack99]

for 3 6th level characters
3 times 6 = 18.
18 divided by 4 = 4.5

for 5 6th level characters
5 times 6 = 30
30 divided by 4 = 7.5

Dont forget that other things can affect the ECL of characters. 32+ point buy is +1 ECL (arguably), also if they have an aboundance of magic items (read much more than the average values), you should bump the ECL by one as well.

 

[TessarrianDM]

for 3 6th level characters
3 times 6 = 18.
18 divided by 4 = 4.5

for 5 6th level characters
5 times 6 = 30
30 divided by 4 = 7.5

Dont forget that other things can affect the ECL of characters. 32+ point buy is +1 ECL (arguably), also if they have an aboundance of magic items (read much more than the average values), you should bump the ECL by one as well.

So, my party of 3-14th, 5-13th and one 10th level characters has an ECL of 29.25 and not the 15.5 as calculated by the penpaperpixel.org Encounter Calculator? That just sounds way too high, considering that they have a hard time with encounters in the CR 20 range. When I plan encounters using the 15.5 figure that the Encounter Calculator gave me , they seem to be more appropriate challenges for the level (a little low from a "use up 25% of party resources per encounter" standpoint, but I can work with that).

The encounter calculator I use is at penpaperpixel.org/tools/d20encountercalculator (sorry, not computer literate enough to post a link ). I believe there are others out there that are available for free (search for d20 encounter calculators). It has definitely reduced my encounter planning headaches.

 

[irdeggman]

for 3 6th level characters
3 times 6 = 18.
18 divided by 4 = 4.5

for 5 6th level characters
5 times 6 = 30
30 divided by 4 = 7.5

Dont forget that other things can affect the ECL of characters. 32+ point buy is +1 ECL (arguably), also if they have an aboundance of magic items (read much more than the average values), you should bump the ECL by one as well.

Not really the method to be used.

I asked Skip (the Sage) that one a while ago since our group was about 7-8 PCs.

The "correct" method is to use the EL tables (with mixed pairs) and back it out.

The "simple" method is to calculate the avg (total ECL/total # of characters) and then add 1 for every additional 2 PCs (over 4). But round down.

My house rules were the simple method and a note to ensure that no single CR exceeded the highest ECL character by more than 2. Also the specifics had to be looked at to ensure that the CR creature could axtually be "hurt" by what the PCs had available. Ensuring that the party could cast spells of appropriate level, etc.)

 

[Thurbane]

I always find this site extremely useful:

d20 Encounter Calculator

 

[thorian]

I always find this site extremely useful:

d20 Encounter Calculator

That is actually the site that caused my question. I was wondering how they calculated the result.

 

[Nifft]

That is actually the site that caused my question. I was wondering how they calculated the result.

The script that contains their formulas is here:
http://www.penpaperpixel.org/scripts/encounterCalculator.js

Cheers, -- N

 

[Thurbane]

I suspect it just adds up total levels and divides by number of members, but check the script to be sure.

 

[Ogrork the Mighty]

There are EL generators out there. I'd use one of those.

 

[blargney the second]

I like Cheiromancer's system:
1) Square each PC's level.
2) Add all those squares together.
3) Take the square root of that sum.
4) Divide it by 2 to get the effective average party level.

Example:
6 PC's levels {6,7,7,8,9,10}
1) Squares {36, 49, 49, 64, 81, 100}
2) Sum squares {379}
3) Square root {19.5}
4} Divide by 2 for effective party level {9.8}

So a single high CR 9 or low CR 10 should take up 1/4 of the party's resources, all things being equal.
-blarg