These rules supercede rules in the booklet that comes with the City of Peril map set.
Narrow buildings and back alleys provide a multileveled skirmish battleground, as your creatures battle between and atop the buildings.
Rooftop Terrain
A single rooftop is a contiguous group of rooftop squares. The ground is comprised of all non-rooftop squares.
Line of Sight and Line of Effect:
When determining line of sight between different rooftops, or between a rooftop and the ground, line of sight is blocked if it crosses two edges of the same rooftop square (or a corner of such a square). Rooftop squares block line of sight between two points on the ground the same way wall squares do. Line of effect is similarly blocked. Rooftop squares do not block line of sight or line of effect to other parts of the same rooftop.
Cover:
Rooftop squares do not provide cover between creatures on the same rooftop. In all other cases, rooftop squares provide cover. Thus, a creature on a rooftop will always have cover versus an attacker that is not on the same rooftop.
Charging:
Rooftop squares prevent a nonflying, non-Incorporeal creature from charging between a rooftop and the ground, and vice versa. Rooftop squares do not block charges between two creatures on the same rooftop. A creature's charge movement can't be used to climb ladders or cross bridges.
Adjacent:
Rooftop squares are not considered adjacent to ground squares.
Bordered By:
Non-rooftop squares that are bordered by a rooftop square also count as bordered by a wall.
Melee Attacks and Melee Reach:
A creature on a rooftop square can't make melee attacks against a creature that isn't on a rooftop square, and vice versa. A creature on a rooftop square can't use Melee Reach to deliver a touch spell to a creature that isn't on a rooftop square, and vice versa.
Cone and Line 12 Effects:
If the originating creature of a cone or line 12 effect is entirely in ground squares, the origin point for the cone or line 12 is considered to be on the ground, even if it is a grid intersection shared by both a ground square and a rooftop square. In this case, the cone or line 12 effect won't be able to affect rooftop squares that are not at the very edge of a rooftop; line of effect from an origin point on the ground to "inner" rooftop squares will be blocked by the "outer" rooftop squares.
Movement:
Flying, burrowing, and Incorporeal creatures can move into rooftop squares freely. Other creatures that are entirely on the ground cannot do so, and must use ladders (see below) or other effects (such as dimension door) to get onto rooftop squares. Nonflying, nonburrowing, non-Incoporeal creatures that are entirely on ground squares can't move diagonally past the corner of a rooftop square. Push/pull effects can't move a creature that is entirely on the ground into a rooftop square.
A creature must end its movement entirely in rooftop squares or entirely in ground squares. It can't end its movement in a position where it is on both a rooftop and the ground. A creature that somehow ends its turn only partially on a rooftop is immediately placed in the nearest legal position that isn't on rooftop and then takes 10 damage.
A nonflying, nonburrowing, non-Incorporeal creature on a rooftop that moves into a non-rooftop square is immediately placed in the nearest legal position that isn't on rooftop, and then takes 10 damage. (For Medium or smaller creatures, the nearest legal position will generally be the creature's current position.) A creature on a rooftop that is forcibly moved into a non-rooftop square is similarly affected. A creature on a rooftop that is not routing cannot voluntarily move into a non-rooftop square if it would be destroyed by the damage.
Climbing Up Ladders:
A creature in a ladder square can spend 2 squares of its movement to climb up the ladder. First, the creature provokes attacks of opportunity from all enemies that threaten its starting space. Then place the creature on the rooftop in a legal position next to the ladder square. If no such legal position exists, leave the creature in its starting space.
Climbing Down Ladders:
A creature on a rooftop and next to a ladder square can spend 2 squares of its movement to climb down the ladder. First, the creature provokes attacks of opportunity from all enemies that threaten its starting space. Then place the creature on the ladder square in a legal position. If no such legal position exists, leave the creature in its starting space. Climbing down a ladder does not deal damage the way moving from a rooftop to the ground does.
Crossing Bridges:
Wooden planks serve as bridges linking the buildings. A creature in a rooftop square at the end of a bridge can spend 3 squares of movement to cross the bridge. First, the creature provokes attacks of opportunity from all enemies that threaten its starting space. Then place the creature in a legal position in the rooftop square at the other end of the bridge. If no such legal position exists, leave the creature in its starting space.
Rooftop Terrain Diagram
Creatures A, B, E, and F are on rooftop squares; creatures C and D are at ground level.
Creatures B, C, D, E, and F can all trace line of effect to one another. Creature A can trace line of sight only to creature B, and creature B is the only one of those creatures that can trace line of sight to creature A.
If A targets B's square with a cone, that cone will not affect C, D, E, or F.
If B targets C with a cone, starting from the grid intersection between them and nearest the plank artwork, that cone will hit C, D, E, and F (because that intersection is both a roof and ground intersection, it affects creatures on both levels).
If creature F makes a ranged attack against creature D and traces cover from either its top corners, then creature D would not have cover.
Additional Comments
Although a non-routing creature is not allowed to "drop" itself off a rooftop if the damage would destroy it, no rule precludes routing creatures from doing so. In fact, if dropping off a rooftop would get a routing creature closer to its exit than any of its other routing movement options, it must drop off that rooftop and take the appropriate amount of damage as it routs. This might even destroy the routing creature.
You can think of bridges and ladders as being mechanically similar to teleporters. When a creature uses a bridge or ladder, you pick it up from its starting position and set it down in its new position. The creature doesn't actually move through the intervening squares. Although this isn't necessarily 'realistic', it achieves the map's design goals using fewer rules.
These rules state that ground squares count as bordered by a wall if they are bordered by a rooftop square. As a result, a Shadowdancer that is entirely on the ground can use Shadow Jump travel to another ground square (that borders a rooftop square, of course). However, a creature isn't allowed to use Shadow Jump to travel from a ground square to a rooftop square (or vice versa) unless some actual wall terrain borders the rooftop square. (Elemental Wall, perhaps?) Similarly, a creature with the Wall Walker ability generally won't be able to gain Flight if it starts its turn in a rooftop square.
DDM Gaming Discussions
