Chiller087, ok, so the sly marine is not as sly as I thought. Thank you, anyway, it's good to have an official answer.
polymythic, that makes sense. So in our group, I guess, the rule will sound like "a ranged attack from, into or through an engaged tile with a friendly force suffers -10 penalty to RS. A ranged attack through occupied tiles without any friendly models suffers -2 penalty for each tile".
I'm not sure if a model can use a ranged attack into the same tile it is standing on. Even using a shotgun ability "pointblank shot" a model should use its CC to make an attack. Otherwise, marines and predators have an opportunity to attack twice during one turn - using RS and CC.
Of course models can make
Of course models can make both close combat and ranged attacks during one turn. But if models can do all types of attacks in one tile it seems to overpower them, as I see it. Not that much for marines, but for a predator hunter this means 6 attacks with some good chances to hit. I just can't understand how aliens can win with such rules. But, sure, may be I'm wrong. Only a lot of playtests can give an answer - or somebody of authors of the game, they've done a lot of playtests already.