Movement and damage delivered during combat is turn based, NOT simultaneous, meaning if you can fell your target before their turn, then you will not have to worry about any damage from that opponent.

The short and sweet description of movement and combat:
-Roll Initiative.
-Combatants move in order from lowest initiative to highest.
-Combatants then attack in order of highest initiative to lowest.

The nitty gritty detailed description of movement and combat:
One round of combat is divided into 4 quarters, with each quarter divided into two parts: Movement, then Activation & Attack.

Initiative:
To determine the order in which people move or strike, all participants must roll initiative at the start of combat. To determine your score: Roll a D20, add your effective level and your wisdom modifier, along with any additional bonuses & penalties you may have (The “Improved Initiative” feat gives you +4 to your Initiative check). The higher your initiative score, the greater your advantage during combat. Initiative is rolled every four rounds. Anybody entering an already ongoing combat will roll initiative when they arrive.

Movement phase:  (Options)
Each player may move up to their full movement during this phase (if your movement is 30, you move up to 30 each quarter). Players with the lowest initiate move first, and the players with the highest initiative will move last. No player may choose to delay taking their movement when it is their turn. Either they move, or they don’t. This benefits players with the highest initiative to strategically choose their position on the battlefield after “slower” persons have already declared their hex.
Note: You may move through a friendly ally’s hex as if the hex was empty (unless they choose not to allow you to pass), provided you have enough movement to finish on an unoccupied hex.
Note: Players with higher initiative have the option to change the order to move before “slower” players (in case there is a specific spot they wish to occupy before an opponent takes it – this will be addressed further below: Movement Addendum 1).

Activation & Attack:  (Options)
Each player has at least one attack to spend per round, and they may spend their attack(s) in any quarter they wish (no more than one attack per quarter may be spent – no bi-phase required between quarters). You may spend an attack by: 1)attacking; 2)casting a spell; 3)Using a speciall skill or feat that costs you an attack to perform. The order in which combatants attack has the player with the highest initiative attacking FIRST, with the lowest initiatve attacking last. Any player may choose to delay their attack, allowing other players/enemies to attack before them that quarter. If however there is a conflict in the order due to people wishing to delay, the person who started the attack phase with the higher initiative gets their way.
Note: Special conditions will apply for players who have situations that would allow them more than one attack a quarter (i.e. players with more than four attacks per round, players with double-ended weapons, and players who wish to attack with two weapons. This will be addressed below: Attack Addendum 1).

Each player also has one free activation per round (there are magic items, skills, feats, and spells that can be used during activation) which may be spent during any quarter. Players use their activation during their combat turn (before they spend an attack if they are also spending an attack that quarter).

An example “Order of Combat”:
First – all combatants roll initiative:
Villain Scores a 10
Hero Scores an 11
Heroine Scores a 12

The Order of Combat for the next four rounds will be:
Movement order from lowest to highest
Movement: Villain (10)
Movement: Hero (11)
Movement: Heroine (12)
Attack order from highest to lowest
Activation & Attack: Heroine (12)
Activation & Attack: Hero (11)
Activation & Attack: Villain (10)

Movement Addenum 1: If a high initiative player wishes to change their position on the list in order to move before another player with lower initiative during movement (i.e. Heroine wishes to move before Villain because she wishes to occupy a doorway before villain can move through), they may do so, however they will likewise be re-ordered in the combat half of the quarter (in game mechaincs, the DM will lower the players initiative score, and thus that will result in a change in their movement and attack position). This change will be permanent until initiative is rolled again. Players may ONLY choose to change their movement in front of players with lower initiative. When in conflict, the player who started the movement phase with the higher initiative gets their way. In the example below, Heroine has chosen to move BEFORE Villain, but as a result, she will now attack last instead of first.

New Adjusted Order:
Movement: Heroine (Score lowered to 9.99 – Originally 12)
Movement: Villain (10)
Movement: Hero (11)
Activation & Attack: Hero (11)
Activation & Attack: Villain (10)
Activation & Attack: Heroine (Score lowered to 9.99 – Originally 12)

NOTE!!!!! You only really need to worry about this procedure if you want to move before an enemy. You generally don’t need to worry about this process if you just want to move before an ally (your DM will assume all PCs are coordinating their efforts together). In the event of conflict, the DM will then go through the formal process.

Attack Addendum 1: For situations where a player could make more than a single attack a quarter, that player cannot attack more than once if they moved more than one hex that quarter.

Attacks of Opportunity:
Each player also has one free “Attack of Opportunity” (AOO) that can be spent each round (There is a feat that players can select called “Combat Reflexes” that will allow more free AOOs). This attack MUST be a melee attack, and can only be spent when a target does an action that provokes an attack of opportunity. Your AOO is resolved immediately and BEFORE the provoking action is resolved. A few examples of actions that provoke attacks of opportunity are:
-A ranged Attack
-An unarmed Attack
-Casting a spell
-Grappling
-Rising from a prone position
-Moving out of melee from an opponent (or moving through a threatened hex adjacent to an enemy).
Note: You will only get to spend an AOO if you are in melee with the person provoking the attack.
Note: AOOs can NOT be spent during your turn. They can only be spent during the turn of the target that is provoking. If someone next to you starts casting a spell, you may spend your AOO immediately. However during your turn, you cannot run up to someone who is in the middle of casting and immediately spend an AOO. You must wait until it is their turn to see if they continue/finish the spell. If so, that is your chance to spend the AOO.
Reminder: Each character (usually) only has ONE AOO to spend, meaning after they’ve spent it, you need not fear performing any other actions that would provoke AOOs from them that round. Your DM may attempt to take advantage of this by having a “tanky” opponent invite you to spend your attack of opportunity on him, and then follow up with softer villains who can then perform provoking actions with no fear of suffering an AOO. This leads to our next reminder…
Reminder: You don’t have to spend your AOO at first opportunity! You may choose to wait for a better opportunity/target, but once you pass on a provoking action, the opportunity is lost (but your AOO is not spent).

Running:
Your normal movement (“Combat Speed”) indicates how fast you can move during combat and continue to attack and protect yourself. However, a character also has the option to run at x2 their normal combat movment, at the expense of losing their dex armor class, shield armor class, and all attacks as they run, and one full round once the run is finished.