Can figures with the Fly ability make an attack from a space occupied by either another figure or an obstacle that blocks movement?

Obstacles yes, figures no. From the movement rules on page 9:

"Figures may pass through spaces occupied by friendly figures during movement, but they cannot attack while in the same space as another figure and they must end their movement in an empty space."

Thanks.

But if a figure with the Fly ability move into a space occupied by an obstacle that blocks line of sight,can I still make an attack from this space?

How to confirm line of sight in that case?

JohannesS said:

It isn't clear in the rules, because they are badly written, but neither the space you are in, nor the target space block LOS. LOS is effectively only blocked by stuff between those spaces, even though the line is drawn from centre to centre.

This is the only way the rules can make sense and work coherently, particularly as in later expansions there are spaces any figure can enter that block LOS (trees). Not only does the game entirely and unresolvably break down if figures in trees can't attack into or out of, but trees have special rules (shadowcloak) that change the effect of attacks on them, something entirely redundant unless the tree itself doesn't block LOS into or out of its own space.

So the rules cover that you cant be in the same space as a figure and attack. What happens if a flying figure enters a space that blocks movement and gets stuck? Either by a guard+web attack? Or if a figure becomes grappled over water/rubble?

Too many times in RtL has this happened. A flying monster will travel over the large water tile and then get stuck.

I have handled it by declaring that until the monster gets free from the web, it cannot attack. Too busy fending off blood squids to worry about attacking something else.

Jonny WS said:

Well, there are a couple questions in the GLoAQ that could potentially be relevant to these:

Can a fiendly figure move through a space occupied by another friendly figure that is currently being grappled?

Yes. Grapple can only hold one figure per space, however.

Can a Hero with Acrobat open a door in which both spaces in front of the door are occupied by creatures, as long as he does not end his turn in one of those spaces?

yes and yes. If this causes a hero to become paralyzed or something due to a trap, simply have the Overlord move the hero to the nearest empty space of the overlord's choice.

I believe I've played in the past that a figure accidentally left in an illegal position moves to the closest legal space of the opponent's choice, but that you can't be grappled over water or rubble (as you can't be grappled while moving through an ally's space).

Corbon said:

Well, figures and trees clearly don't block LOS in the origin or target space. Fog, on the other hand, seems to be intended to do so (unless the origin and target spaces are adjacent). In my opinion, we don't have any particularly solid indications one way or the other for rubble, though I think I've generally allowed attacks in or out of a rubble space in the past.

There's a discussion thread about hopefully getting this issue addressed in a future FAQ update. With, logically enough, posts by me and Corbon.