sage

I think that the root of my problem is described in your first paragraph. I think a better implementation would be either any part-to-any part. This would solve the Asymmetrical problem, and it would also solve the case mentioned previously where a tiny bit of cover was completely blocking a shot. This might exacerbate the case where troops that are covered are otherwise treated as unprotected. Beyond that, there are some very weird shots (impossible) shots I've seen occur, such as dual keyhole shots (I.e. through two windows at different levels, and then across open ground). I think that could be solved via a simple rules based check -- i.e. you can only shoot through a window on a different level; or at a target on a different level fro the window; at a target that is adjacent to that window. Finally, I have definitely seen cases that break the example that Chris has given, always involving an AI shooter. I saw one last night where an exposed alien shot through a window at a target adjacent to that window; the alien definitely did not have LOS to the center point of the targets square. All of these exception cases and bugs are happening often enough that the game isn't fun. I might be able to adjust my play-style and tactics to work around these issues (as it seems many people are or are suggesting), but I want to be able to use something like real world breach and clear tactics I learned in the army. XCOM's abstract system for handling these things is also kind of Janky and is occasionally unpredictable, but overall seems to be more consistent.

Thanks for the link. It's illogical (IRL all of Chris's examples would happily be able to blaze away at each other; a shooter would simply position themselves to be able to fire effectively and be covered - center mass is not a criteria for being able to shoot) and a bad game play decision to boot (bad means it seems to often result in unpredictable outcomes, e.g. my eye tells me I'd be in cover and be able to shoot, but in fact I'm neither in-cover nor shooting). Bummer. (edit for clarity)

While this seems kind of janky at best for a tactical game (there are other ways this could be abstracted with good effect), it still doesn't explain what I'm seeing -- which is that Line-of-Fire is not bidirectional. The system you're describing should basically allow / disallow shooting between two squares, regardless of the direction of fire. That doesn't appear to be the case.

I think that this is a symptom of the issue I'm describing here: http://www.goldhawkinteractive.com/forums/showthread.php/10511-Xenonauts-V1-04-Released!?p=116225#post116225 Basically, the 'can-shoot' calculation works differently for aliens than for soldiers, resulting in times when an alien can shoot and target a soldier who cannot shoot back.

That still doesn't make sense. If what you were describing were the case, the corner-shooter should have *cover*, but not be effectively invulnerable. What I'm seeing is that sometimes (but not every time) the corner shooter is invulnerable. The corner-shooter is going to be vulnerable both when the lean around the corner to acquire a target, then shoot and vulnerable to high velocity rounds penetrating interior walls. This would be simulated by a % penalty to hit.

That's fair. I'm not actually certain that this is a LOS issue now, since the alien IS spotted; it's just that it can't be shot at directly, but it can shoot back effectively. Is there something different in the code about how the alien 'can shoot' check is made vs. player?

It doesn't simulate any such thing -- an Alien can shoot a soldier, but the soldier can't shoot back? If what you're suggesting were true, both would be able to shoot each other. It's almost like this works differently for soldiers vs. aliens.

Wonky LOS fix? I've repeatedly run into problems with wonky line-of-sight killing my troopers. The most common case is that my trooper can't shoot an alien that it CAN see; but the alien CAN shoot the trooper. This seems to always happen where there's a corner involved. After playing through half-a-dozen tactical battles and having more than half of my casualties due to this, I rage-quit, and haven't been playing. But that's a bummer, because the game seems really good other than that!