Mapping For CTF

Capture the Flag (CTF): Two teams both have a movable flag that's planted on an immobile flag base. A team scores a point by getting both flags to their home flag base.

From Deathmatch to Capture the Flag

On the surface it may seem like a CTF map is simply just an elongated DM map with a couple of flags and team spawn points thrown in for good measure. Unfortunately this is not the case. When mapping for a DM map the flow of the level has to be considered in its entirety. There shouldn't be any choking points on the map and few (if any) dead ends. CTF maps on the other hand thrive on natural choke points and have, by their very nature, at least two dead ends (ie. the flag rooms). The only important map flow is between the two flag bases.

Creating a CTF Map

When building a CTF map there are a number of things that are vital to its success. These are summarised below.

The flag room and the location of the FlagBase object within it.
The location of the team spawning points.
The route(s) from a flag room into the central area (if there is one) of your map.
The balancing of the map and its weapons so that neither team has an advantage over the other.
The LevelInfo has the DefaultGameType set to xGame.xCTFGame?

The Flag Room

There are two styles of flag room you can use. You can either build a flag room that is relatively open and reasonably large (e.g. Orbital, and Command), or, you can go for a smaller flag room with obstacles (e.g. Coret, and Gauntlet). Neither type of flag room is particularly advantageous to the attacking or defending team. At this point advantage goes to whichever team is best in the flag room environment itself.

The flag room should have some health and ammunition available to the defenders, and possibly a low powered weapon (such as the Pulse or Bio Rifles). The more powerful weapons should be placed away from the flag, or in an awkward position. This means that a flag's defenders must be out of position to obtain them, placing the flag at some risk.

And finally, although it seems obvious, there should be no question in a player's mind as to which team the flag room belongs to. It should be completely obvious. Placing the flag on an obvious feature or making it the centerpoint of the room is also a good idea - it serves to emphasise the location of the flag. Just ensure that the feature used for this purpose doesn't obstruct the player unexpectedly (the flag holder on Coret is a bugger for that).

Team Spawn Points

Spawn points need to be carefully placed. Place them near the center of a map and the defence will have an easy ride. Place them behind the flag, or level with the flag, and the attackers will have a far easier job escaping with the flags as the defence may not be able to catch up with the escaping flag carrier. Generally spawn points should be placed around the flag room (but not necessarily within it) but no closer to the center of the map than about half way through a base. It's generally better to favour the attacking team when placing spawn points though as this ensures the focus of the defence is on defending the base.

Routes Between the Flags

How the routes between the two flag rooms are constructed will determine how your map flows, and how it is paced.

If you want a fairly slow pace then the central area between the two flag rooms should be very open, and long. The cover available to the flag carrier and his team mates should be extremely limited. In this type of map there is normally only a single choke point – the central area. CTF-Hydro is a good example of this type of map. The bridges are really the only choke point in the level. If you control them you control the game.

A good example of a medium paced map is CTF-Coret. The level is mainly corridor based with the central area having plenty of pillars and cover for the flag carrier. The map also has multiple routes between the flag rooms. The are plenty of opportunities to move between the different routes between the two flag rooms, which helps the flag carriers escape. There are two choke points in Coret, one in each base. Each choke point is located just after the first door to each base. The choke point is located at the ramp that links the upper and lower routes. At the top of this ramp you can see everyone attempting to take the top route, and hear people coming through the door trying to take the lower route.

Fast paced maps are always small. Both open and corridor fast paced maps exist, and both work well when done right. Maps of this form are almost exclusively based on a figure of eight, or, a straight line with occasional obstacles. CTF-Gauntlet and CTF-Niven are good examples of this type of map.

Probably the best models to use when creating your routes between the flags are one or more figure of 8's, or a braid type structure. CTF-Command and CTF-Gauntlet are classic figure of eight maps. CTF-Coret is much closer to the braid model as it has multiple cross over points and loops.

The routes between each of the flag rooms should be team coloured at each end, and neutrally decorated in the center of the map. If it's a large map consider putting obvious markers on walls that lead towards the flag rooms. A player should never been in doubt as to which flag room they are heading towards.

Map Balance – Symmetry or Asymmetry

The debate about map symmetry for CTF games has raged long and hard. Rather than become embroiled in a discussion that is well outside of the scope of this page I'll side step the issue. Some points worthy of consideration are listed below.

Asymmetrical maps take forever to balance correctly and are harder to build well.
It is important that both teams have equal access to weapons, health, and armour – even if the map is asymmetrical.
A map that is symmetrical in structure does not necessarily have to be symmetrical in terms of theme.

Personally, I would recommend making your maps symmetrical: that way you can be completely sure that the map is balanced. The symmetry can be:

simple: The bases face each other. The MapScale tool can be used to quickly make one base a mirror image of the other.
rotational: drag-select the entire base, duplicate, and rotate to make base number two.

Diagonal lines of symmetry (bases at right angles), or bases one above the other are also sometimes seen. Be careful when building map bases above each other. Although it seems that the lower team has an advantage because their flag carrier can escape more easily, this is not the case. The lower team will be overwhelmed by players from the upper team dropping into their base - by simply falling. The upper team's ability to field players more quickly makes covering the flag carrier much easier and more than offsets the lower teams ability to escape faster.

If you do decide to build an asymmetrical map you absolutely must ensure that it gets extensively play tested by clans that play regularly in leagues and ladders.

Item Placement

Make sure both bases have equal amounts of health, weapons, armour, and other items that can be picked up. If the map is symmetrical then the objects should be as well. Make sure that there is enough ammunition and health for the number of players you envisage using the map. Also, make sure there are enough player starts. You might think your map shouldn't be played by more than 8 people at a time, but at some point someone will play it with 16.

Make sure you have enough PlayerStarts and that you assign them for each team. Don't make a red team member spawn in the blue base or vice versa.

Team 0 is Red
Team 1 is Blue

Troubleshooting

Some known problems with CTF levels:

Bots won't get the flag

Try moving the end of your flag further into the floor. Don't worry about the overlap with geometry. It won't cause BSP holes. It's also worth checking the bot-paths as displayed within the path view. You can find the path view toggle within the Viewport Caption Context Menu. You may find that you don't have a path to the flag.

Bots only take one path

Try using AlternatePath actors and setting a priority on them. You can also put items on an alternate path to entice bots towards that direction. Also allow for translocation points and distance shooting for bots.

The flag has fallen into a pit and is stuck there

Make sure that all falls and drops have a PainZone? at the bottom - that way the flag will be returned when it drops into it. A map that suffers from this problem is CTF-High.

Or, make sure that the ZoneInfo(lava pressure vaccum etc) in the area you want the flag to be returned has to have bStatic = True in the advanced properties.