Firstly, my problem is that I was thinking that the "invisibility" was like that of the predator's; that when they move, you can kinda see/hear them, hence the 10 and 20 Spot/Listen checks within 30 feet, but my players are looking at it as more of a LOTR/Clash of the Titans thing as where the only way you can track them is by the sounds of footsteps, moovement of foliage or something, and footprints. What I'm really looking for is and easy to understand chart or specific directions because I don't like the way I've been doing it. What I would do is a PC would drink a potion of invisibility. We'd leave their miniature there. They would move or then move then attack or whatever, citing what they would do for rules clarification. If they moved or attacked, any NPC within 30 feet is entitled to a Spot/Listen check of DC 20 to find their general location. After everything is understood to be OK, they'd write down the number of where they are at (my mat has numbered hexagons which is convenient for this) and keep it secret. My NPCs would have to guess (by choosing a hexagonal number) of where the PC is. Roll the attack to see if it would hit their AC. Roll the miss chance of 30% (which I'm not sure if I'm doing it right, but, to me, 01-30% is a hit and 31-100% is a miss, so I'd like that clarified), and then they tell me if I hit them, then I would roll damage.
I know I screwed up by giving them access to so much invisibility stuff because I didn't take into account how powerful it was. Mistake cited, heh.
The other thing is the PC who is a drow started out as a blind character and has Blindfight as a feat and letting him be blind for so long, I've let him not suffer penalties in melee and stuff like that, but when he casts darkness and he is the only one who can really do anything, it's really, REALLY annoying. I've been deducting the bonus XP I would normally give him because it's really annoying for him to take over the combat by doing that. I can understand when he is at 2 HP fighting an EL 13 and doing it for survival, but just doing it 'cuz he can is soooo annoying and I would like more information on how I can fix it so that he's not the only one who can do something or so that he has SOME type of penalties.
Yeah ... I think that's it for right now. So, let me know what you think and any info would be REALLY appreciated.