All of this comes directly from the Pathfinder PRD. This is a very good page and worth a read, but I've sumarised what you really need to know below. If you're confused about anything, consult your GM.
How Combat Works
Combat is cyclical; everybody acts in turn in a regular cycle of rounds. Combat follows this sequence:
1. When combat begins, all combatants roll initiative.
2. Determine which characters are aware of their opponents. These characters can act during a surprise round. If all the characters are aware of their opponents, proceed with normal rounds. See the surprise section for more information.
3. After the surprise round (if any), all combatants are ready to begin the first normal round of combat.
4. Combatants act in initiative order (highest to lowest).
5. When everyone has had a turn, the next round begins with the combatant with the highest initiative, and steps 4 and 5 repeat until combat ends.
A combat round translates to about 6 seconds. During a round, you can do any of the following:
Search for !!! to skip to a list of examples of each action type. If uncertain what an type of action something is, consult your GM.
If you have not taken a move action, you may take a "Five foot step" for free. In essense, you move five feet (1 square) in a direction of your choice. This must be taken on your turn, but can be before or after you perform any other actions.
Movement:
This is one of the most important things for you to describe. Ideally, the GM will provide a battle grid for you to draw your exact path on to avoid this.
Halflings and Gnomes move at 20ft (4 squares) per round when wearing light or no armour and not encumbered. Otherwise, they move at 15ft (3 squares) per round.
Dwarves always move at 20ft (4 squares) per round.
All other races move at 30ft (6 squares) per round when wearing light or no armour and not encumbered. Otherwise, they move at 20ft (4 squares) per round.
You can move past your friends freely, but not through squares occupied by your foes unless you are good at acrobatics.
Moving on diagonals is quite permisable, but since they are slightly longer, every second diagonal you move along costs 2 squares of movement rather than 1.
Sometimes there are things that hinder movement, such as trees or bushes. Your GM will tell you how much they slow you by.
Combat Advice
Here are a few things that make sense in to do combat (They're just like Real Life! Amazing!):
If someone is firing arrows at you, hide behind a tree. If you're behind a tree, it's harder to hit you. Of course, you can't hit them so easily either. Works both ways. The same holds with melee weapons.
If you have multiple attackers surrounding a single defender, it's a lot easier to hit them (they can't dodge things they can't see). Two attackers coming at the enemy from opposite sides is the way to go, so attack from behind!
If you fall asleep or unconscious in combat you're totally helpless and easy pickings.
Dropping to the ground is great for avoiding ranged attacks, but you're an easy target for people close up.
Attacks of Opportunity
If you do anything that would leave you unable to defend yourself (Such as drinking a potion, moving past an enemy, casting a spell, &c.), enemies that are able to hit you in melee can attempt to do so for free, taking advantage of the opportunity to attack (hence the name). You can of course do the same to them, should the situation arise.
You can take only one attack of opportunity per round unless you have the Combat Reflexes feat. Unless you specifically tell your GM otherwise, they will assume that you take the first attack of opportunity you can.
As a beginner, the most important thing to take from this is that you should move up to enemies to hit them, but not past them if you can help it.
HP Clarification
You are completely fine (or at least, suffer no ill effects) right up until your HP is reduced to 0. When it hits 0, you are disabled. You are still alive and conscious, but performing anything strenuous will cause you to start losing blood and consciousness (and HP).
Strange as it may sound, you can actually survive for a while below 0 HP. You are alive right up until your HP is equal to -1 times your constiution (eg you have a con score of 14, so you die at -14 HP). One you are bought below 0 HP, you bleed out your HP at the rate of 1 HP per turn unless stabilised.
You can stabilise naturally, although this is unlikely unless you have a high Con score. Otherwise, another character can stabilise you with the Heal skill. Any sort of Healing that restores 1 or more HP also stabilises you.
For Spellcasters
Casting spells next to monsters is dangerous since it leaves you undefended, and worse, can make you lose concentration. If you lose concentration, you lose the spell. Luckily, there is an option to "Cast Defensively". That is, you try to defend yourself while casting the spell. You still need to concentrate, but at least you aren't going to be hit.
Other actions
There are, if indirectly, rules for pretty much anything you might want to do in battle, be it walloping people with chairs, pushing them off cliffs, draging them kicking and screaming through a horde of goblins, holding them down and pouring beer down their throat, smashing their weapon, grabbing their wallet or my personal favourite, kneeing them in the groin. There can be much more to combat than just swinging a pointy metal thing around, so be imaginative!
!!!
Examples of standard actions:
Examples of move actions:
Examples of Complex actions (also called full-round actions)
You can do the following things freely and as much as you could realistically do in 6 seconds regardless of what else you do
How Combat Works
Combat is cyclical; everybody acts in turn in a regular cycle of rounds. Combat follows this sequence:
1. When combat begins, all combatants roll initiative.
2. Determine which characters are aware of their opponents. These characters can act during a surprise round. If all the characters are aware of their opponents, proceed with normal rounds. See the surprise section for more information.
3. After the surprise round (if any), all combatants are ready to begin the first normal round of combat.
4. Combatants act in initiative order (highest to lowest).
5. When everyone has had a turn, the next round begins with the combatant with the highest initiative, and steps 4 and 5 repeat until combat ends.
A combat round translates to about 6 seconds. During a round, you can do any of the following:
- Perform a full attack (You attack multiple times if possible)
- Perform a standard action and a move action (or just one of these)
- Perform a complex action
- Move up to four times your speed (Running)
Search for !!! to skip to a list of examples of each action type. If uncertain what an type of action something is, consult your GM.
If you have not taken a move action, you may take a "Five foot step" for free. In essense, you move five feet (1 square) in a direction of your choice. This must be taken on your turn, but can be before or after you perform any other actions.
Movement:
This is one of the most important things for you to describe. Ideally, the GM will provide a battle grid for you to draw your exact path on to avoid this.
Halflings and Gnomes move at 20ft (4 squares) per round when wearing light or no armour and not encumbered. Otherwise, they move at 15ft (3 squares) per round.
Dwarves always move at 20ft (4 squares) per round.
All other races move at 30ft (6 squares) per round when wearing light or no armour and not encumbered. Otherwise, they move at 20ft (4 squares) per round.
You can move past your friends freely, but not through squares occupied by your foes unless you are good at acrobatics.
Moving on diagonals is quite permisable, but since they are slightly longer, every second diagonal you move along costs 2 squares of movement rather than 1.
Sometimes there are things that hinder movement, such as trees or bushes. Your GM will tell you how much they slow you by.
Combat Advice
Here are a few things that make sense in to do combat (They're just like Real Life! Amazing!):
If someone is firing arrows at you, hide behind a tree. If you're behind a tree, it's harder to hit you. Of course, you can't hit them so easily either. Works both ways. The same holds with melee weapons.
If you have multiple attackers surrounding a single defender, it's a lot easier to hit them (they can't dodge things they can't see). Two attackers coming at the enemy from opposite sides is the way to go, so attack from behind!
If you fall asleep or unconscious in combat you're totally helpless and easy pickings.
Dropping to the ground is great for avoiding ranged attacks, but you're an easy target for people close up.
Attacks of Opportunity
If you do anything that would leave you unable to defend yourself (Such as drinking a potion, moving past an enemy, casting a spell, &c.), enemies that are able to hit you in melee can attempt to do so for free, taking advantage of the opportunity to attack (hence the name). You can of course do the same to them, should the situation arise.
You can take only one attack of opportunity per round unless you have the Combat Reflexes feat. Unless you specifically tell your GM otherwise, they will assume that you take the first attack of opportunity you can.
As a beginner, the most important thing to take from this is that you should move up to enemies to hit them, but not past them if you can help it.
HP Clarification
You are completely fine (or at least, suffer no ill effects) right up until your HP is reduced to 0. When it hits 0, you are disabled. You are still alive and conscious, but performing anything strenuous will cause you to start losing blood and consciousness (and HP).
Strange as it may sound, you can actually survive for a while below 0 HP. You are alive right up until your HP is equal to -1 times your constiution (eg you have a con score of 14, so you die at -14 HP). One you are bought below 0 HP, you bleed out your HP at the rate of 1 HP per turn unless stabilised.
You can stabilise naturally, although this is unlikely unless you have a high Con score. Otherwise, another character can stabilise you with the Heal skill. Any sort of Healing that restores 1 or more HP also stabilises you.
For Spellcasters
Casting spells next to monsters is dangerous since it leaves you undefended, and worse, can make you lose concentration. If you lose concentration, you lose the spell. Luckily, there is an option to "Cast Defensively". That is, you try to defend yourself while casting the spell. You still need to concentrate, but at least you aren't going to be hit.
Other actions
There are, if indirectly, rules for pretty much anything you might want to do in battle, be it walloping people with chairs, pushing them off cliffs, draging them kicking and screaming through a horde of goblins, holding them down and pouring beer down their throat, smashing their weapon, grabbing their wallet or my personal favourite, kneeing them in the groin. There can be much more to combat than just swinging a pointy metal thing around, so be imaginative!
!!!
Examples of standard actions:
- Attack with a weapon
- Cast most spells (The spell says if it takes anything other than a standard action)
- Use a Class Ability (unless you're told otherwise)
- Use an item in your hand
- Defend
Examples of move actions:
- Move up to your speed
- Stand up
- Draw/sheathe a weapon (If you are level 2+ or a fighting character you can do this as you perform some other move action)
- Pick up an easy to reach item (such as from the ground or hanging from your backpack)
- Open/close a door
- Mount/dismount a horse
- Load a light or hand crossbow
Examples of Complex actions (also called full-round actions)
- Charge (Run in a straight line and attack)
- Use a touch spell on up to 6 friends
- Light a torch
- Use a Skill
- Escape from a net
- Load a firearm, Heavy or repeating crossbow
- Crawl 5 feet
You can do the following things freely and as much as you could realistically do in 6 seconds regardless of what else you do
- Drop an item
- Drop to the floor
- Speak (or yell)
- Prepare spell components
