Mapping For BR
In Bombing Run (BR) two teams face off against each other in large arena-like levels. A ball is spawned at the center of the level. The object of the game is for one team to carry the ball to a hoop in the opposing team's base (the goal) and either carry it through the hoop (worth 7 points), or, fire the ball through the hoop (worth 3 points). Once a team has scored the players are re-spawned at their starting points after 5 seconds or so and the ball is re-spawned in the center of the map.
Map Structure
Bombing run maps by their very nature tend to be composed of large rooms rather than small cramped corridors. Space is needed to allow the ball to be passed between team members. Multiple levels within a BR map can work very well but should be used with care as it would be possible to make it far too easy to score.
Framerate is the biggest thing to watch for in a Bombing Run map. Because the rooms are so large it's easily possible to either pack in too much detail, or, allow players to see from one end of the level through to the other (always a frame rate killer).
Think very very carefully before making an assymetrical Bombing Run map – you may break the gameplay compeltely.
The specific areas of the map are discussed below.
The scoring hoop
Probably the most important thing to remember about the positioning of the scoring hoop is that it should be difficult to throw the ball through, and much harder for a player to actually carry the ball through. Having some sort of penalty (like death) for carrying the ball through the hoop is fine – just a bit gimmicky. Placing the scoring hoop at the end of a long thin ramp with certain death on either side is also fine.
Probably the most important thing to remember is that it should be impossible to score from a great distance. The ball can be thrown a long way. Teams really shouldn't be able to throw the ball from one end of the level to the other and score bypassing the defense.
It's possible to have more than one scoring hoop per team. Several maps out there take advantage of this fact, though it's questionable if it enhances gameplay any.
Player start points
There should be an identical number of player start points for each team, and they need to be placed in exactly the same relative positions from the ball spaw point. Otherwise one team may be able to reach the ball spawn point much faster than the other team, gaining a big advantage.
Players start points should be close enough to a weapon that one can easily be grabbed. Ideally there should also be a selection of routes to the ball spawn point. The distance between the player start points and the scoring hoop also needs careful thought. If the player start points are too close to the scoring hoop then attackers will have a very hard time scoring as they will be wading through multiple waves of defenders.
The ball spawn point
Currently there can be only one of these on a level. At the start of each round (or when the ball is reset) this is the point at which the ball is respawn. The bigger the area the ball spawns in the less like a spam-frag fest round starts will be. It should be possible to pass the ball out of the spawn room quickly. The first person to touch the ball is almost certainly going to die very shortly after picking it up.
ShootSpots
Bots require ShootSpots in the map to play correctly. A ShootSpot should be placed in an area where a bot can shoot the ball straight at the opposing goal, preferably near the goal with a better-than-decent chance of scoring. A BlueShootSpot will fire at the blue goal, Red at the red goal; although bots from either Team will use the ShootSpot if distressed. Bots from the Blue Team shooting from a BlueShootSpot will try to launch the ball straight at the red goal, effectively 'punting' the ball to the other side of the map. Note: Bots will do this whether the map blocks a clear, straight shot to the goal or not. When placing ShootSpots, be aware of the line as well as the arc that bots will try to launch the ball at in order to hit the opposing goal from that point. (I hope that makes sense. Just play test with xBombDelivery→TouchdownDifficulty set to 1 and you'll see the bots try to shoot more often. –SuperApe) More than one ShootSpot can be placed per goal.
Summary
I can envisage all sorts of inventive ideas for ball spawn points and map features. Out of all of the game styles, Bombing Run probably lends itself most to the creation of one-off features that aid the gameplay.