Shin Okada said:
I see, he is using "sniping" in PHB P.76.
I think the player is trying to be clever and get around the sniping rules. Here's how you do it:
First, you start off hidden behind total cover such as around a corner or behind a tree. On your turn you:
1) Use a free action to lean around the corner to see your target. [See Note A]
2) Use your standard action to attack the target with SA damage. At this point the enemy can see you, but you don't care.
3) Use a move action to go back behind the cover. Since you are in total cover again, you automatically succeed at your Hide check.
Rince and repeat
While you should need a new Hide check in step 1, because you are in improved cover, you get a +10 bonus which makes it even harder for the bad guys. If you were going to be super-strick, you could say that since you are moving from one form of cover to another (total to improved) you need to make a new Hide check and making a Hide check requires a move action. Forcing this would limit the rogue to one attack every other round.
To deal with this problem you have a few choices. First, you can deny the sneak attack damage to all but the first attack since your opponent is now expecting it. Secondly, you can use readied actions to attack the rogue (remember to include the +8 AC bonus). Enemy mages can use properly placed burst or spreads to reach around the corner. You probably wouldn't want to use a spell with a Reflex save so Sound Burst and Stinking Cloud are good low level choices. Alchemist fire can be a poor man's substitute. Finally, the best bet is to just throw a sight blocking spell in the general area to take the rogue out of the fight. Obscuring Mist is the classic choice but a smokestick can be used by the magically challenged.
If the character were to use the sniping rules, he wouldn't be able to duck back behind the cover and so would be left semi-exposed (still with improved cover).
Are there rules written that allow a character the made a Spot check to inform others of the hidden character's location?
Note A: While leaning around a corner isn't something you can normally do if you play strictly by the miniature rules, "peering around a corner" is specifically mentioned on pg. 152 as an example of improved cover. The above scheme won't work under the mini rules, the rogue would have to make a 5-ft. step to move around the cover thus losing his cover and blowing his hidden status.
Aaron