Pathfinder on Roll20

This guide only discusses how to play Pathfinder RPG with the Roll20 virtual tabletop. You can find all of the Pathfinder RPG rules (free!) on Paizo Publishing's Pathfinder Reference Document (PRD). Of course, hardcover books are available from paizo.com or your friendly local game store.

Setting up your Character Sheet for players

There are several ways to set up the player character sheet. Most important is that the GM makes it available to the player. A good way for the GM is to have a general Player Character Sheet made already, and simply duplicate it, and give permissions as suited. Normally those would be that All Players can see, the relevant player can edit.

Basically your entire Pen&Paper character sheet can be added in Roll20. The things you need to figure out as a GM when making the standard, is how much effort you (and your players) should do to make the character.Questions you can ask yourself to find out what you need on your character sheet and how detailed it should be:

Is it a one time campaign?
Will the campaign stretch over several levels?
Will you have the same players playing every time?
Are the characters supposed to be low or high level?

If it's only a one-shot campaign, you might not need such elaborate character sheets. The basics would probably suffice, with Ability modifiers, HP, AC, maybe even Base Attack Bonus. The corresponding macros usually aren't that complex either, but they would still be time-saving. If, on the other hand, you're going to take your normal Pathfinder-group online, and keep on playing, level after level, hour after hour, getting the Character Sheet right, already at start, is extremely time-saving.

Example of a Character Sheet going for the long run

You would probably find (or create) a nice picture for your Character, type in some bio that you have planned, and start with the automation on the "Attributes & Abilities"-tab.

The list of Attributes could look like this:

HP 26/26
AC 18
Level 3
High Save
Low Save
Base Attack Bonus 3
Strength 2/15
Dexterity 1/12
Constitution 0/11
Intelligence -1/9
Wisdom 1/13
Charisma -2/7
Long Sword 1d8
Weapon Focus (Long Sword) 1
Weapon Specialization (Long Sword) 2
Masterwork +1
Short Sword 1d6
Magic Enhancement +1
Lightning Damage 1d6
Two Weapon Fighting -2
Ring of Protection +1
Breastplate AC +6
Breastplate Check Penalty -4

Notes:

The Ability scores is written "backwards" because it's the modifier which is used, and not the score. This way you can keep track of score (when it gets modified) while the modifier is used.
Normally a Fighter would simply use Level instead of Base Attack Bonus, and not need this at all, but since this is an example this is added, so it's easier to switch to other classes.
If there's planned multiclassing, it might be easier to simply use Fortitude, Reflex and Will, than High and Low Save.
Instead of Long Sword and Short Sword, you might consider using "Weapon", as it's easier to change the weapon in the macros, unless you do like this guy, and go all in on Long Sword, which means he will probably use this weapon forever. Protip: Use "Weapon 1", "Weapon 2" and such, and keep on the Bio (or in the macro) which weapon is which.
It's practical to have the stuff that changes in the top, so if you have created them in another order, simply drag the ones you change most often to the top by hovering the abilities you want to move, and drag the three lines that pop up in the right end, to where you want them.

Setting up Macros in Abilities

There's two ways of saving macros in Roll20, that both can be found very useful in your session.Normal marcos, found under My Settings in is mainly used by players, and only to give the abilities a shorter name in the macro quick bar. But mainly both players and GMs should keep to using Abilities on the Character Sheet. When using abilities together with attributes, you get a quick way of doing "everything" with your character.

With the Character Sheet above us, we can make the player really effective, and we don't need to wait for the slow calculation of adding it all up. You can even add some flavor text with the /me-functionality.

Example of Abilities

Attribute: Full Attack

/me does a mighty strike with his Long Sword, and his glowing Short Sword!
/r 1d20+@{Base Attack Bonus} +@{Strength} +@{Weapon Focus (Long Sword)} +@{Masterwork} +@{Two Weapon Fighting} vs. AC To hit with Long Sword. Critical: 19-20x2
/r @{Long Sword}+ @{Strength} +@{Weapon Specialization (Long Sword)} Damage with Long Sword.
/r 1d20+@{Base Attack Bonus} +@{Strength} +{Magic Enhancement} vs. AC To hit with the Short Sword. Critical: 19-20x2
/r @{Short Sword} +@{Strength}/2 +@{Lightning Damage} +{Magic Enhancement} Damage with Short Sword.

This gives you the two hits, both damages if they are hits, and everything with no math involved. Note that if you didn't use Base Attack Bonus on your character sheet, use level instead of base attack bonus, like this: /r 1d20+@{Level}+@{Strength}.... Another strenght of this way of doing it, is that every time you wonder how you got to that number, you can simply check everything in the macro, and it's easy to remove and add effects and modifiers for later time. Say to get the Long Sword enchanted, simply remove Masterwork and add the Magic Enchantment Bonus.

You can also use the Attributes for way more than just "simple" attacks.

Grapple

/me tries to grapple his opponent as best he can.
/r 1d20+ @{Base Attack Bonus} + @{Strength} vs CMD.
When grappled does not break the grapple in the first round, the grappler gain a +5 circumstance bonus.
Grappled Condition
A grappled creature is restrained by a creature, trap, or effect. Grappled creatures cannot move and take a –4 penalty to Dexterity. A grappled creature takes a –2 penalty on all attack rolls and combat maneuver checks, except those made to grapple or escape a grapple. In addition, grappled creatures can take no action that requires two hands to perform. A grappled character who attempts to cast a spell or use a spell-like ability must make a concentration check (DC 10 + grappler's CMB + spell level), or lose the spell. Grappled creatures cannot make attacks of opportunity.
A grappled creature cannot use Stealth to hide from the creature grappling it, even if a special ability, such as hide in plain sight, would normally allow it to do so. If a grappled creature becomes invisible, through a spell or other ability, it gains a +2 circumstance bonus on its CMD to avoid being grappled, but receives no other benefit.
Casting Spells while Grappled/Grappling: The only spells which can be cast while grappling or pinned are those without somatic components and whose material components (if any) you have in hand. Even so, you must make a concentration check (DC 10 + the grappler's CMB + the level of the spell you're casting) or lose the spell.*Pinned Condition
A pinned creature is tightly bound and can take few actions. A pinned creature cannot move and is denied its Dexterity bonus. A pinned character also takes an additional –4 penalty to his Armor Class. A pinned creature is limited in the actions that it can take. A pinned creature can always attempt to free itself, usually through a combat maneuver check or Escape Artist check. A pinned creature can take verbal and mental actions, but cannot cast any spells that require a somatic or material component. A pinned character who attempts to cast a spell or use a spell-like ability must make a concentration check (DC 10 + grappler's CMB + spell level) or lose the spell. Pinned is a more severe version of grappled, and their effects do not stack.
Casting Spells while Pinned: The only spells which can be cast while grappling or pinned are those without somatic components and whose material components (if any) you have in hand. Even so, you must make a concentration check (DC 10 + the grappler's CMB + the level of the spell you're casting) or lose the spell.

Casting Spells both damaging and non-damaging:

/me mumbles on Arcana, claps his hands together, and a thick obscuring mist quickly spreads out from him in 20. ft radius.
A misty vapor arises around you. It is stationary. The vapor obscures all sight, including darkvision, beyond 5 feet. A creature 5 feet away has concealment (attacks have a 20% miss chance). Creatures farther away have total concealment (50% miss chance, and the attacker cannot use sight to locate the target).
A moderate wind (11+ mph), such as from a gust of wind spell, disperses the fog in 4 rounds. A strong wind (21+ mph) disperses the fog in 1 round. A fireball, flame strike, or similar spell burns away the fog in the explosive or fiery spell's area. A wall of fire burns away the fog in the area into which it deals damage.

Initiative:

/me throws himself into the battle, as soon as he figures there's gonna be a fight!
/r 1d20 + @{Dexterity} Initiative

Skill checks:

/me taking a jump.
/r 1d20+@{Dexterity} +@{Level} +3 -@{Breast Plate Check Penalty}
You can jump your jump score in feet long, and one fourth of the jump score high.

Checking the AC, to see why your AC is what it is, or if you have forgotten to update it:

/me simply checks his AC
/r 1d1-1 + 10 + @{Dexterity} +@{Ring of Protection} +@{Breast Plate AC}

Throwing saves, and remembering all the effects that we so often forget:

/r 1d20+@{High Save} +@{Constitution} Fortitude Save
Remember +2 vs poisons and sleep effects

A quick reminder on what to do when leveling up:

/me has DINGed! DINGDINGDING!
/r 1d10+@{Constitution}
http://www.d20pfsrd.com/classes/character-advancement
http://www.d20pfsrd.com/classes/core-classes/fighter
Checklist: HP (Check),Level, Favored Class Bonus, Skill Ranks, BAB, Saving Throws, Feats, Class Features, Spells, Consequnses of these changes that doesn't go with the sheet, (extra language for upped in Int, and such).

Messages you use often or often enough (as you can have as many as you could ever want):