Hey S'mon!
S'mon said:
I think... each PC is CR = Level, but to get the party EL I need to translate CRs into ELs? So 1 5th level PC is EL 10 by U_K system, so 4 would be, er, no...
I add together the CRs/Levels, so 4 x5 = 20, then take away 4, = 16? So 4 5th level PCs are CR 16? So their EL is 17? I have a headache now...
Its all very simple...take a deep breath and look at the top of the right hand column on page 15. It takes you through the 3 steps.
Step 1: Add all the CRs.
eg. x3 5th-level PCs and 1 6th-level PC (all with standard point buy which is +1 CR)
Total 25 (5+1 + 5+1 + 5+1 + 6+1)
Step 2: Convert to Encounter Level using table 2-1.
eg. CR 25 = EL 19
Step 3: Modify for the number of characters using table 2-2.
eg. Party of Four Characters = EL -4.
So EL 19 - 4 = EL 15
The party of 3 5th-level and 1 6th-level character are EL 15.
So if you want to set them a moderate encounter use EL 11 = single monster of CR 6 (by my system)
eg. Green Dragon Wyrmling, Basilisk, Troll, Vampire Spawn etc.
If you want a tough encounter (or WotC moderate encounter) use EL 13 = single monster CR 8-9 (by my system)
eg. Very Young Black Dragon, Chuul, Bearded Devil, Megaraptor etc.
If you want a difficult encounter use EL 15 = single monster of CR 12-13 (by my system).
eg. Very Young Red Dragon, Athach, Erinyes, Tyrannosaurus etc.