Dispell and line of sight to the enemy caster

[HispaZargon]

Well, in NA edition they removed such rule... or not exactly! In NA if a Hero opens a door, he reveals all the contents of the room, so actually it means that all of them can be seen by the Hero, aren't they? Again, for me it leads me to think that it is not the same 'seeing something' than 'being in the Line of Sight of something'. During a game I try to distinguish if a spell requires 'seeing' the target or 'being in the target in the Line of Sight'. For example in NA edition I understand that any Monster in a room can be affected by a Sleep spell since it only requires that the target must be 'seen' by the spellcaster, however not all the monster can be attacked by a Genie spell, since the second explicitly requires the target to be 'in the Line of Sight'. This approach solves 99% of doubtful situations about casting spells.