I want to make sure I understand scaling between 4 players and 5 players.
Determine the total XP award for the encounter by looking up its CR on Table 12-2. This gives you an "XP budget" for the encounter.
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For example, let's say you want your group of six 8th level PCs... table 12-1 tells you that a challenge rating for an APL 9 group is CR 10 encounter - worth 9,600 XP
So how this works is the number under the "Individual XP" is multiplied by the number of PCs.
So a CR 3 encounter has a budget of 800 XP for 4 players. However a CR 3 encounter has a budget of 800 XP for 5 players.
Is that correct?
If so, then a CR 3 encounter for 4 players becomes a CR 2 for 5 players. Because 800 divided by 5 is 160 (10 XP over a CR 2). Does that sound right?
My apologies if this is a horribly obvious question, but I just want to make sure I understand the process right. I come from D&D 4th ed and the process above is how it works in 4th ed. So I want to make sure it's the same for Pathfinder.
Note that these encounter creation guidelines assume a group of four or five PCs.
Four or five, it's the same thing. You got it that CR3 is 800. Then divvy up that 800 however you like. Two CR1 monsters at 400 each = 800, for example.
No, a CR 3 encounter for 4 players is still a CR 3 encounter for 5 players. If you had 6 or more PC's, the CR would still be CR 3, it just wouldn't be as much of a challenge (since a group of six or more PC's is considered to be 1 higher party level for determining challenges). If you are using the budgeting method for determining encounters, it doesn't matter if there are 4 or 5 PCs. For a party of 5, each individual PC would just get fewer XP's for the given encounter. It makes for slightly slower advancement, unless you compensate by adding a few 'easy' encounters (CR's at -1 APL or less) to make up for it. A good way to add treasure if a lot of your heavier encounters are with treasureless creatures.
I'll caution GMs though---depending on who the extra members of a party are, a 5 member party may be considerably more than 25% stronger than a 4 member party, especially if the 5th is a force multiplier class like a bard.
+1
Another way to do it that is more complex, but it's what I use with bigger parties rather than just adding 1 to the APL, is figure out the CR of the party (like if it were monsters), then subtract 4 to get the APL.