I was playing wyverns in a custom scenario, and saw an enemy on the edge of the map away from any blocked tiles, hit him with a Wild Spark, but it only did 3 damage. Intentional?
I can sort of see why it would be, but it feels weird nonetheless. In staying with the visual rules the game implies, wouldn't the edges need to be denoted by a solid black line?
Yes, a non-existent square is counted the same as a blocked square. Functionally, it's the same (i.e. you can't move onto it, you can't trace line of sight through it, etc).