Flanking with Ranged Attacks

[bagger245]

How does it work actually? My friend is adjacent to an enemy and I am in flanking
position, but do I have to be adjacent liek a pair of rogues or can I be say, 5 squares
away?

 

[Starglim]

To flank an enemy, you and an ally must be adjacent to the enemy

The rest of the section is also worth reading. Note that there are several other ways that a rogue can gain combat advantage against an enemy.

 

[Kordeth]

In order to flank, you must fulfill two criteria:

1) You must be able to attack the flanked creature.

2) You must be adjacent to the enemy with an ally adjacent to it on the opposite side or corner.

In other words, yes, you still have to be adjacent to flank even if you are armed with a ranged weapon.