For reference, this is the proposed FAQ:
Quote:
Q: When is a unit in cover? A fraction of the model, more than half, fully?
A: For infantry, they can gain concealment to-hit benefit from simply touching an AV, so it makes sense that would be the standard for claiming the to-hit penalty for any terrain. As long as they touch the terrain, they can claim the benefits. To claim a cover save, infantry must be partially within the terrain.
For vehicles, impassable terrain works based on the "hull down" rules and whether the terrain obscures the model. For dangerous terrain there is a relatively easily determined standard based on the dangerous terrain check. If the model at least touches the terrain and is willing to take a dangerous terrain check, it can claim the cover benefits, i.e. no cover benefits without taking the terrain penalty. For terrain that has no effect on vehicles but might provide cover, it is best to remain consistent with infantry and dangerous terrain for vehicles and simply declare that a vehicle touching the cover can claim the benefit.
As always, though, terrain should be part of the 5 minute warmup. Players will have to work out, for example, whether touching the base of a piece of terrain counts as touching it, or if the model would need to butt up against the actual terrain feature itself rather than just the base. The answer might even be different from terrain piece to terrain piece. For example, the entire base of trees may count as being in the trees, but the base surrounding a building does not.
I would also note the design concept sidebar in the rules state that the -1 to-hit mod should be applied generously.