Combat will be run on a hex map (when I feel the need to map out combat).
All characters and monsters will have a facing during combat. This means you face toward one adjacent hex. All three hexes in front of you are considered front hexes, which means you attack and defend at no penalty with respect to these hexes. The next hex on either side is a flanking hexes, which means you attack at a -4 to these hexes and opponents there get +2 to hit you (and can sneak attack). The last one is a rear hex, where you cannot attack (without feats to allow it), you are denied Dex to AC, opponents get +2 to hit, and you may be sneak attacked.
You may change your facing a fixed number of times per round (as an immediate action). You may change it as part of your move action or a 5 foot step, and as a immediate action once per attack granted you by your BAB. So a character with a BAB of +6, may change facing twice per round as a free action, +11, three times, and so on. Changing your facing may also provoke attacks of opportunity if an enemy is in your rear hex during or at the end of the facing change.
Flanking with another character: you receive a +1 to hit when at least 2 hexes around from an ally character working with you, +2 for opposite sides (3 away). Flanking bonuses from multiple allies do not stack, but all allies receive the highest bonus applicable (3 allies working together with 2 of them opposite each other all receive +2).
Feats and Skills
To go along with these rules, a mix of feats and skill uses will be offered to allow you to try and avoid getting sneak attacked all day long (or do it to someone else).
Uncanny Dodge: Bonuses to hit you from flanking/rear hexes are reduced to +1, you retain Dex to AC. Prerequisites: Only gained as a class ability.
Improved Uncanny Dodge: Opponents receive no bonus to hit you from flanking/rear hexes, can only be sneak attacked from rear. Prerequisites: Only gained as a class ability.
Eyes in the Back of Your Head: Retain Dex to AC, can attack flanking hexes at -2, rear hex at -4 Prerequisites: Dodge, Mobility, Combat Expertise, BAB +4
Whirlwind Attack: One attack at full BAB against every opponent in reach Prerequisites: Dodge, Mobility, Combat Expertise, Eyes in the Back of Your Head, Spring Attack, BAB +4
Dervish: All hexes are now considered forward facing hexes now, you can only be sneak attacked by rogue four levels higher and flanking (or when flat-footed) Prerequisites: Combat Reflexes, Uncanny Dodge, Dodge, Mobility, Spring Attack, Combat Expertise, Eyes in the Back of Your Head, Whirlwind Attack, BAB +10