I agree to not punish a character for a good strategy. Ways to challenge him might be to have at least one scenario a night where a archer doesn't do well. Some thoughts to challenge the archer with the environment would be:
A narrow tunnel 10 feet wide where the front line make it harder to shoot past them
A large area for combat where the front line cannot keep the bad guys away from the archer
Enemies with DR good/silver/or anything the archer doesn't have. A lot of monsters have hard DR and throwing them the party's way is fair game
Ambushes where the front line cannot establish itself
All of these ideas don't punish the character for a good strategy nor do they get to specific against the archer (monks snatching arrows, cutting bow strings, etc). By changing the battle ground a little to not always favor the archer it could make things interesting. I imagine the party really relies on the archer's damage. If the archer is engaged in a melee combat it might put the preasure on the entire party.
David
A narrow tunnel 10 feet wide where the front line make it harder to shoot past them
A large area for combat where the front line cannot keep the bad guys away from the archer
Enemies with DR good/silver/or anything the archer doesn't have. A lot of monsters have hard DR and throwing them the party's way is fair game
Ambushes where the front line cannot establish itself
All of these ideas don't punish the character for a good strategy nor do they get to specific against the archer (monks snatching arrows, cutting bow strings, etc). By changing the battle ground a little to not always favor the archer it could make things interesting. I imagine the party really relies on the archer's damage. If the archer is engaged in a melee combat it might put the preasure on the entire party.
David