How to Design an Encounter

Pathfinder simplified as well as streamlined the encounter system. However, while the CR system is a good estimate, it is by no means perfect or a law to be blindly followed. The PrP policies allow you to use as many or as few monsters as you need to create a challenge and entertaining encounter for your players. Ultimately, there is no better way to get a feel for what works and what doesn't than experience running plots.

How to Calculate the Challenge Rating for an Encounter

1. First, calculate the Average Party Level, or APL. That is, total the levels of each player character in the plot, then divide the end result by the number of players, and round it to the nearest number (not necessarily down).

Decrease the APL by 1 if:

The number of players is 3 or less

If circumstances are heavily slated against the player characters

Increase the APL by 1 if:

If there are 6 or more players

If circumstances play heavily in their favor

If the characters are stronger than average (this applies to most Tenebrae PC because of the higher point buy)

2. Next, compare this modified APL with Table: Experience Point Awards. Look at the "Total XP" column. For example, if your modified APL was 6, then you have an "XP Budget" of 2,400.

3. Open the Bestiary. Choose monsters that you feel fit the storyline. Total the individual XP values of each monster. Then, compare the end result with your "XP Budget" number. Once you're close to your number, you've "filled" the monsters for that encounter.

Don't worry if the value isn't exactly equal--just approximate it the best you can.

Note: The above method can be done in reverse as well--starting with a target CR and breaking down its XP value into individual monsters.