Guys, could we talk about how cover and intervening props work?

Okay dokey, first thing people need to do is make sure they know how accuracy is calculated. (Regardless of how outdated it is).

Other people have discussed what I would call "target range" accuracy formulae, where there are no intervening props or any cover between target and shooter. But I haven't seen any discussion on what happens when there are intervening props or cover, and I think it's past due time to do so.

Now, I've been fiddling about with lasers, making them as uber accurate as people want them to be, but there's a big ol' stumbling block to making uber accurate weapons. Props and cover cut massive chunks off the % to-hit. Let's say that solider X has a 95% chance to hit alien Y. Stick a prop in the way which has a 50% chance to block a shot, and solider X now has a 45% chance to hit alien Y (as there is a straight 50% chance that the prop will block the shot). So, ow, it doesn't matter how accurate you make a weapon, props really get in the way (I should know - I've been fiddling!)

What's really OTT is if alien Y is hiding behind cover Z as well. Because then you take into account the "cover save" of the object, which is cover stopping chance/solider stopping chance (60%). I suspect that's wrong, because ay caramba, a piece of terrain with a stopping chance of 50% would provide a cover save of .83! You'd never hit a baddy and a baddy could never hit you! I rather think it's cover stopping chance * solider stopping chance, giving a more respectable .3.

So if you combine a single intervening prop with a stopping chance of 50% (and there's plenty of that in industrial and terror maps) with a piece of ordinary cover with a stopping chance of 50%, then a hit chance of 95% sinks like a stone to 15%, and there's nothing you can do about it. Well.. except hypervelocity-tagged weapons. Because they just pass through intervening terrain, making AP missiles very useful at winkling out entrenched bad guys.

Now that's a pretty persausive argument for flanking a baddy. Cover most ineedly rawks, and props have a significant effect on a shot. But do they have too much of an effect? Is there room for moderation?

Okay dokey, first thing people need to do is make sure they know how accuracy is calculated. (Regardless of how outdated it is).

Other people have discussed what I would call "target range" accuracy formulae, where there are no intervening props or any cover between target and shooter. But I haven't seen any discussion on what happens when there are intervening props or cover, and I think it's past due time to do so.

Now, I've been fiddling about with lasers, making them as uber accurate as people want them to be, but there's a big ol' stumbling block to making uber accurate weapons. Props and cover cut massive chunks off the % to-hit. Let's say that solider X has a 95% chance to hit alien Y. Stick a prop in the way which has a 50% chance to block a shot, and solider X now has a 45% chance to hit alien Y (as there is a straight 50% chance that the prop will block the shot). So, ow, it doesn't matter how accurate you make a weapon, props really get in the way (I should know - I've been fiddling!)

What's really OTT is if alien Y is hiding behind cover Z as well. Because then you take into account the "cover save" of the object, which is cover stopping chance/solider stopping chance (60%). I suspect that's wrong, because ay caramba, a piece of terrain with a stopping chance of 50% would provide a cover save of .83! You'd never hit a baddy and a baddy could never hit you! I rather think it's cover stopping chance * solider stopping chance, giving a more respectable .3.

So if you combine a single intervening prop with a stopping chance of 50% (and there's plenty of that in industrial and terror maps) with a piece of ordinary cover with a stopping chance of 50%, then a hit chance of 95% sinks like a stone to 15%, and there's nothing you can do about it. Well.. except hypervelocity-tagged weapons. Because they just pass through intervening terrain, making AP missiles very useful at winkling out entrenched bad guys.

Now that's a pretty persausive argument for flanking a baddy. Cover most ineedly rawks, and props have a significant effect on a shot. But do they have too much of an effect? Is there room for moderation?

Shooter Accuracy * Accuracy Modifier * (Range to Target / Weapon Operational Range) = Unmodified Accuracy

The Wiki formula (above) is wrong, BTW. It should read like this:

Shooter Accuracy * Accuracy Modifier * (Weapon Operational Range / Range Target) = Unmodified Accuracy

Otherwise weapons would get more accurate as the range increased which we know is not true.

As far as your idea goes I'm not at all in favor of making the props less effective in blocking fire. Many of the alien weapons and some of Xenonaut weapons a raw to hit chance of 20% all the way across the map. Without intervening props being highly effective it would become a game where the only thing that mattered would be who had the highest firing rate and the most weapons. With the current accuracy formulas the ONLY thing that allows to manuever your troops is using cover. If cover was less effective then it would suicidal to close with the enemy. My own personal feeling that the accuracy formula should be changed to something like the one I proposed here http://www.goldhawkinteractive.com/forums/showthread.php/4275-Shot-Miss-Scattering?p=56806&viewfull=1#post56806, but I don't think that is going to happen.

I haven't proposed any ideas, at least, I don't think I have (I hope I haven't). I have, I hope, shown how props and cover work at the moment, and would like to ask the burning question, is it too much? I mean, I don't want a shooting gallery, that's for certain, but, y'know, 20%'s when shooting are pretty common across the board, and it's easy for that to sink down to 10%s and less. It's one of the reasons that LMGs and rockets are so valuable. The LMG can fire lots of shots, and rockets just either blow away or ignore cover/props. It's one of the reasons that tier 4 gear is so valuable, because all of tier 4 has the hypervelocity tag. I just think that it's perhaps a little too much towards blocking shots. Bear in mind that the props+cover rule is also applied to grenades.

I haven't proposed any ideas, at least, I don't think I have (I hope I haven't). I have, I hope, shown how props and cover work at the moment, and would like to ask the burning question, is it too much? I mean, I don't want a shooting gallery, that's for certain, but, y'know, 20%'s when shooting are pretty common across the board, and it's easy for that to sink down to 10%s and less. It's one of the reasons that LMGs and rockets are so valuable. The LMG can fire lots of shots, and rockets just either blow away or ignore cover/props. It's one of the reasons that tier 4 gear is so valuable, because all of tier 4 has the hypervelocity tag. I just think that it's perhaps a little too much towards blocking shots. Bear in mind that the props+cover rule is also applied to grenades.

Yes, I would like to see the effectiveness of intervening props reduced in effectiveness. However, I am uncertain as to whether it is right to see the effectiveness of intervening props reduced. But let me put forth my argument for reducing the effectiveness of intervening props. Thusly.

It doesn't matter a damn how accuracy is calculated, so long as intervening props and cover are never part of that calculation.

Two examples. Example 1. Grenades. When a grenade is thrown, it has to take a "block test" against each intervening prop with a progressively higher stopping value. That's why a grenade may begin to sail out in an arc, then come to a grinding halt a square away and detonate, because it didn't pass the "block test" of the 50% stopping chance flowerbed the squaddie throwing was a square away from.

Example 2. There is a cap of 95% for any "to-hit" roll. I purposly cranked up the accuracy of lasers so that if an alien was out in the open, there was always 95% chance of hitting it on the minimum setting. But if I draw a line through an intervening prop, the stopping chance of that prop is a straight deduction after accuracy is calculated. Thus, the flowerbed with a 50% of blocking drops that 95% to 45%. If you hide behind cover, with a modest 30% or less, (say 25% , which is the minimum), the chance to hit drops to 20%. The thing is, intervening props and cover is a common sight, and not just in the indisutral maps. In the desert bases, cover always forms a block of 3-5. Each prop that isn't cover is an intervening prop, which gets in the way and adds to the chance to miss. You can have the most skilled solider in the world, with the most accurate weapon in the world, calculated using the most elegant accuracy formulae in the world, and none of that matters a damn the moment a prop gets in the way. At all.

To be honest, cover isn't as effective as an intervening prop at reducing the to-hit. The "saving throw" of cover is a product of cover stopping chance and squaddie stopping chance, which reduces the effective stopping chance of cover. Intervening props are always calculated on the full stopping chance of the prop, so it's actually better, in a wierd way, to whever possible take cover by stopping a square away from a prop, rather than hiding behind it.

I agree that "intervening props" vs "cover" impacts accuracy too much.

Actively hiding behind a wall, rock, crate, etc seems fine as is. Given limited poses and the fact we have suppression (flank!) or explosives (ignore!) to deal with cover makes the game more interesting.

What sucks is when your rifleman loses 20% here and 20% there due to a fence in the way or a flowerpot or whatever, so by the time you get to the cover the target is actively hiding behind the chance to hit is minimal. Maybe upping suppression on rifles might help, so you're not just firing for nothing, but providing support for assault/grenadiers? Snipers (aside from laser, should we say all precision rifles should have hypervelocity?) can essentially bypass minor props.

I didn't know about that last bit about being a step behind cover... that does seem broken.

I think cover itself could use slight improvement, and intervening objects should be less of an obstacle. In some cases, it doesn't really make sense for multiple intervening objects to count--if I can avoid hitting the waist--high brick wall, why should the flowerpot further decrease my accuracy? I might miss and hit that object, but it shouldn't be counted as an additional obstacle.

That might be difficult to code, though. I'd maybe reduce the effectiveness of (some) intervening objects by 10 or 20%, and increase the effectiveness of actual cover by the same.

Two examples. Example 1. Grenades. When a grenade is thrown, it has to take a "block test" against each intervening prop with a progressively higher stopping value. That's why a grenade may begin to sail out in an arc, then come to a grinding halt a square away and detonate, because it didn't pass the "block test" of the 50% stopping chance flowerbed the squaddie throwing was a square away from.

Yeah, I think they will be addressing some of this stuff. I've seen a few instances where I have a greater percent to hit an enemy if I fire beyond the target while making sure the target is in the projectile path, than if I fired directly at the target.

it's actually better, in a wierd way, to whever possible take cover by stopping a square away from a prop, rather than hiding behind it.

Are you certain on that?

Because (according to the wiki information added by Chris) if the object you are a tile away from is the same size or smaller than any other object along the fire path it will be disregarded by the accuracy formula.

Being behind it as cover will give you a cover save on top of that accuracy reduction from other props so it appears to me, if everything is working as intended, that using the object as cover should be potentially much more effective.

If you could absolutely guarantee that you would only get shot at from a direction where no other objects would intervene and the object you are stood near would definitely be in the fire path then your example might be right.

If they fired over a barrel, then the shot passed over the barrel you were near that second barrel would be disregarded completely and it would be as if you were stood in the open.

If you were using the barrel as cover that shot, even if classed as a hit, would still have a chance to damage the barrel instead of you.

For grenades I would definitely reduce the stopping chance of any object along the path, with the probable exception of 100% objects.

That could be done in the code properties for bullettype=grenade so it doesn't affect normal weapons that are not expected to have that arc in flight.

Sorry, I should have made that clearer. By "a square away". I mean one distinct tile separating the prop from the squaddie, so that the prop is not counted as cover, but as intervening terrain. Currently, the AI does not take "getting to a better angle" into account but I'll ignore that line of argument - the AI is not finished. Of a more reasonable argument is getting into a better angle around intervening terrain in the first place. It's certainly not always possible to get around intervening terrain. The artic maps with their thick wooded patches, industrial maps littered with goods, middle east maps which are complete villages, terror maps with zoned buildings and parked cars - these are all examples of cover being clumped closely enough together that you can't help but shoot into intervening terrain. Getting around terrain can consume serious TUs (because cover tend to be clumped, although there are notable exceptions) and given the high TU cost of alien plasma weaponry, it seems to be better (from using alien plasma weapons myself) to risk the shot.

However, it's not always possible to assure this, it's just an oddity that if there's intevening terrain, the odds are better because of the way the calculation works.

I dunno, I quite like it how it is. Flanking is pretty important because cover seriously drops hit chance.

Then again, I use alot of Assault troops so moving around cover and fighting at close range is something I'm getting good at.

Sorry, I should have made that clearer. By "a square away". I mean one distinct tile separating the prop from the squaddie, so that the prop is not counted as cover, but as intervening terrain.

I understood that and that was what I addressed in my post.

That intervening bit of terrain you are one tile away from would not be counted in any accuracy calculation if there was another piece with the same or higher stopping value between it and the shooter (assuming it works as described).

The same is not true if you are using it as cover.

It would still not be counted in the accuracy calculation but it would give a cover save with a chance of absorbing damage.

To my mind that means using the item as cover would, in general, be at least as good as standing a tile away and hoping there was nothing else between it and the shooter and would likely be better.

I was wondering if you had tested your statement and found it was actually better or if it was an untested observation.

If it is tested it might show an error in the accuracy calculation.