By standing back-to-back, two people could avoid some combinations of being flanked. Not all combinations, though. (proper placement of battlefield obstacles can further help.) It all depends on the specific layouts.SRD wrote:Sneak Attack: The rogue’s attack deals extra damage any time her target would be denied a Dexterity bonus to AC (whether the target actually has a Dexterity bonus or not), or when the rogue flanks her target.
As for tripping someone, D&D doesn't get that detailed. The person would be considered "prone".
The details of how the person is facing and all that are really up to the DM to arbitrate. I suspect that if you were to declare in your post that you were trying to trip someone in a particular way, it would be taken under consideration. If you score very well on your tripping roll, that would be you doing it the way you wanted.SRD wrote:Prone: The character is on the ground. An attacker who is prone has a –4 penalty on melee attack rolls and cannot use a ranged weapon (except for a crossbow). A defender who is prone gains a +4 bonus to Armor Class against ranged attacks, but takes a –4 penalty to AC against melee attacks.
Standing up is a move-equivalent action that provokes an attack of opportunity.
