So I had a funny situation yesterday. I argued against it because it was a bit too much of an abstraction.

A unit X is on top of a tall building, shooting at a unit Z that's just below it, with only half visible to the squad leader.

My opponent initially argued that it should be counted as "you ignore terrain you are touching with the squad leader for cover to the opponent", while I argued that if the squad leader doesn't have LoS to more than half of the target squad.

Who's right?

It sounds like you're both right?

The squad doesn't get cover for being obstructed by the building, but touching the terrain doesn't allow you to ignore it for line of sight , and the models outside line of sight get heavy cover from that , and can't suffer wounds.

(Side note: a lot people have been running buildings/ruins as consisting of multiple piece of terrain for the base contact rule, to allow stuff like getting cover from shooting through a window at a unit on the other side of a window on the opposite wall.)

There is an interaction between 2 pages at work here for determining cover. The important words are “obscure” and “provide”.

From page 8, when LOS is completely blocked, that terrain provides heavy cover. From page 22, the process of determining cover is first check for obscuring , then check for type of cover provided . Also from page 22, terrain the leader is touching “cannot obscure ”.

So, since the building you are touching does not obscure , you do not check what type of cover it provides .

Your opponent was right as far as cover is concerned. But, as @svelok said, LOS is not actually affected so you can’t apply wounds to the minis you can’t see.

25 minutes ago, nashjaee said:

From page 8, when LOS is completely blocked, that terrain provides heavy cover. From page 22, the process of determining cover is first check for obscuring , then check for type of cover provided . Also from page 22, terrain the leader is touching “cannot obscure ”.

So, since the building you are touching does not obscure , you do not check what type of cover it provides .

Yep, I agree that this is the correct interpretation.

I was under the (incorrect) impression that blocked LoS providing heavy cover was part of the LoS/Blocked rules themselves, when in fact they're (as you explained) part of the terrain rules.

I'm gonna send that in as a rules question, since it doesn't really make sense to me, but it is the correct ruling for now.

Bit of a loophole I think, but OK.

It does seem like the original cover rules were designed mostly just to facilitate the use of terrain pieces like the barricades in the core set; low, well defined walls and other simple pieces with minimal or no elevation changes.

I think a lot of the confusion that has occurred surrounding the cover rules reflect the relative simplicity of the “draw a line” test and it’s inadequecy for dealing with more complex, custom terrain.

You can define more complex rules for more complex terrain as needed.

For a multi story building, you can treat each story as an individual piece of terrain for the leader touching rule.

That way shooting from the second story down into the street, you would ignore any walls and stuff in that story you are on, but shooting through the floor into the story below you would have to give heavy cover.