There is no facing in D&D/PF. This is side effect of the fact that static 6-second rounds do no justice to dynamics of combat. Every character is assumed to move around his square within that 6 seconds, turn and change facing as the needs arise and not waiting ptiently for his turn.
When two allies are on the opposite sides of enemy they flank him because he cannot allow oneself to be facing one and turn his back on the other so he has to stand so they are on his sides and he can look on one or the other OR he has to continue turning from one to another never giving any one of them enough time to get good shoot at his back - think of Jackie Chan movies where he fights multiple enemies: he turns to one opponent, parry attack, immediately turns to another, dodge, turn to another and attack and then turns back to first. Very taxing, very deangerous but better than fight one and get bludgeoned to unconsciousness by all other opponents.
XXX
1A2
X3X
1 and 2 flank A because they are on the opposite sides of the A.
3 Does not flank A because he has no ally on the opposite side. There is no need to remember who was last attacked by A - it is irrevelant for the flanking purposes.
However, the problem with you character might be related to different rules with flanking: you wrote that you are sniper rogue - ranged weapons do not threaten area like melee weapons and thus do not allow for flanking - you are limited to sneak attacks only when opponent loses his Dexterity bonus to AC (because he is flat-footed, stunned, you are invisible, etc.). You can still normally flank and thus add sneak attack damage dice when using melee weapon.
Your rules lawyer is correct, there is no facing in the game. Characters in combat are assumed to be looking all around them at all times.
To gain sneak attack you have to work for it. That usually means flanking, surprise or concealment. Really serious folks playing rogues might even have improved feinting to gain sneak attack.
Flanking rules are well outlined in the book, so I don't see a need to rewrite those rules here, but basically if you and a conscious, armed ally are on opposite sides of the target, and both of you are adjacent to the target, you both gain "flanking" status. It's really pretty simple. You cannot flank with a ranged weapon as far as I know, it has to be a melee weapon.
What it sounds like you are really looking for is how to gain sneak attack, as I said flanking is only one way to do that. Getting surprise or being concealed from the target also works. Anything that removes the dex bonus to armor class also allows you to sneak attack, and there are both spells and actions which can cause that. Feinting allows a sneak attack for that reason.
If you and an ally are opposite an enemy and both of you threaten (typically this means you have melee weapons drawn), that enemy is flanked. There is not any facing in Pathfinder. Being flanked represents that a character is dividing his attention between two foes on opposite sides, thereby making him more open to attack from both of them.
Your best chance to get your extra Sneak Attack Damage is to act first in the round (when your enemy is flat-footed), so get the Improved Initiative feat (combined with your high DEX modifier) to improve your chances.
Your second best chance is to wait for a fighter type to engage the enemy and THEN move in to flank... Now EVERY attack you make will be eligible for extra Sneak Attack damage as long as you are flanking him.
Ultradan
Ah I missed the part where you cant gain flanking advantage with a ranged weapon. Damn. the sniper looks far less cool now, especially with the loss of trapfinding
This is one reason my rogues typically snipe with thrown weapons, then they threaten with the same weapon they use to attack at range. Of course as you can see from other threads, becoming a thrown weapon expert usually requires a fairly heavy feat cost, especially if you also want to be a two weapon fighter.
Ah I missed the part where you cant gain flanking advantage with a ranged weapon. Damn. the sniper looks far less cool now, especially with the loss of trapfinding
Looks less cool, until you get a pair of sniper goggles from the APG and a ring of invisibility. Go invis. Sneak attack out to any distance. Deal extra damage while doing it. One of my players did this rather effectively with a rogue/ranger in Kingmaker.
Ah I missed the part where you cant gain flanking advantage with a ranged weapon. Damn. the sniper looks far less cool now, especially with the loss of trapfinding
You can sneak attack with a ranged weapon but the target would have to be flatfooted or denied dex bonus to AC, and I believe you would have to be within 30 feet.
I know some peps say this is crap, but the gang-up feat may work.
Most people will say you can sneak attack if the enemy does not know where you by using the snipe part of Stealth, but you really need a sick stealth skill to get past the -20 or be a level 10 rogue.
If you can get to the point you can use stealth well than you need to front load all your damage due to the fact you will only get one attack.
Next time you make a ranged rogue you may also want to be a Halfling
Swift as Shadows: Halflings possess incredible stealth even while moving through obstructed areas. Halflings with this racial trait reduce the penalty for using Stealth while moving by 5, and reduce the Stealth check penalty for sniping by 10. This racial trait replaces the sure-footed racial trait.
so a level 10 Rogue halfing can snipe with no negative.
I know some peps say this is crap, but the gang-up feat may work.
Most peps will say you can sneak attack if the enemy does not know where you by using the snipe part of Stealth, but you really need a sick stealth skill to get past the -20 or be a level 10 rogue.
If you can get to the point you can use stealth well than you need to front load all your damage due to the fact you will only get one attack.
Next time you make a ranged rogue you may also want to be a Halfling
Swift as Shadows: Halflings possess incredible stealth even while moving through obstructed areas. Halflings with this racial trait reduce the penalty for using Stealth while moving by 5, and reduce the Stealth check penalty for sniping by 10. This racial trait replaces the sure-footed racial trait.
so a level 10 Rogue halfing can snipe with no negative.
What does peps mean?
people