(Editor’s note: I made a printable copy of the leveling guide as well)
I’ve seen a lot of people struggle with leveling up, and it’s no mystery why: you have to consult several tables spread across the rulebook, and a lot of the bonuses and choices are less than obvious.
I’ve written a simple guide to help you get started leveling your Pathfinder characters (attached in image form, but written below in case you’re on a phone or want to copy it):
Pathfinder Leveling Guide
1. Choose a class
First, decide which class you want to level. You can take a level in one of your existing classes, or take the first level in a new one. If you choose a new one, you must meet the prerequisites for that class. There’s no limit to how many times you can multi-class, but it’s rarely effective to have more than three classes.
2. Feats & Attributes
Consult the Pathfinder Core Rulebook, page 30. Use your TOTAL level on this table and choose the appropriate bonus. Don’t forget to include any attribute modifier changes across your character sheet, like Strength bonuses to attack or Intelligence modifiers to the number of spells you can learn.
3. Take class features
Consult the leveling table for your class. Find the row for your class level (if you’re multi-classing, it’s NOT your total level) and apply the features under ‘Special’ for your class / level combination. Read the descriptions carefully as some of these features require you to make permanent choices.
4. Gain hit points (class + con bonus)
Your maximum HP increases based on the class you chose in step 1. Depending on your DM’s rules, you can take the maximum value for the die or roll it. Next, add your constitution modifier to this value. Add one more if you have the Toughness feat. Finally, add one more if you are leveling your favored class and want to use the bonus for HP.
5. Train skills (class + int bonus)
Train as many ranks as the rulebook states for thse class you are leveling. Don’t forget to add your Intelligence modifier! You may not train a skill above your TOTAL level in ranks. You may use your favored class bonus here if you are leveling in your favored class and don’t want to use it on HP.
6. BAB & Saving throws
Your base attack bonus and saving throws are the sum of the highest values across your class / level combination. Typically these will never go up more than +1 at a time and they might not go up at all. Both values are found on your class leveling chart used in step 2.
If you are leveling a spellcasting class, you need to update your spells according to the “Spells Per Day” table for your class. Sorcerers need to choose which spells they learn. You may need to rest or prepare before your new spells are ready!
8. Tidy up!
You need to update several sections of your character sheet for all of the choices you made and the features you were granted. Update powers that scale with your class level or total level, like the Druid Animal Companion.
I hope this will make your leveling chores a little easier. If you want more detail, as always D20PFSRD has an excellent, thorough guide.