Mapping For 1on1
1on1 deathmatch levels are arguably the hardest to make well. A 1on1 has the tightest margin of error when dealing with flow problems, because the player is more often navigating your level than shooting at her opponent. When a 1on1 map has lousy flow–it's hard to climb that ramp, you get stuck on some trivial decoration–then it's not just a "lame bit" on your map, it's a serious inbitor to gameplay.
Most deathmatch map, but especially 1-on-1 deathmatch maps, are based on a series of major and minor nodes. If you run around in them it's pretty easy to tell where they are. Major nodes are typically multi-level rooms with more than two entrances and maybe some goodie in the middle to tempt people.
Minor nodes are the rooms that usually hold health, powerups, weapons, and most of the PlayerSpawns. Minor nodes are tpyically escape routes, side halls, reloading spots, spawn areas, and "unimportant" rooms. This is where you load up before hunting down the enemy.
A typical 1on1 map has between two and five major nodes and no more than twice that in minor nodes.
A 1on1 map is unique in that it's just you, your enemy, and the level you're fighting in. When you aren't worrying about a bunch of other players shooting you in the face, you can spend time trying to figure out where your enemy is. For instance, all the pickups make a very distinct noise when collected (health vials, for some reason, are particularly loud and easy to pick out), so you can often determine where your opponent is by what things they pick up. You can also track them by the swath of missing pickups (ammo, health, damage amps, etc...) and figure out their cycle around the map. Anyway, the point is, a 1on1 game is much more of a sneaky game of ambush and thinking, rather than quick trigger fingers and flak cannons (those things help, too, you know).
When making a 1on1 map, you should be thinking about how you'd want to play a 1on1 map. The first step should be to make a little diagram of the different major nodes you want, and figure out how you want them to be connected. Mark where you want elevators, important powerups, multilevel rooms, and rooms that have one-way shortcuts to other locations (teleporters, dropshafts, etc.).
The second step is to think about how you want the major nodes to flow together with minor nodes. This, for me, is the hardest part. In many 1on1 maps, the lines are blurred between connector and node. Many 1on1 maps have little symmetry–all the doors and halls are unique. This helps add more flavor than what would otherwise exist on such a small map, and it makes the map seem somewhat bigger than it otherwise would.
When you develop the overall design, you should think about where you want noisemakers. Noisemakers would be any powerup that makes a distinctive noise, or some bit of the environment that reveals the location of the player that triggered it. Adding noisemakers makes a 1on1 map much more interesting. It also plays into the risk-vs-reward principle of mapping, since a player must decide if grabbing that keg o' health is worth walking through that noisy puddle and revealing their location.
Related Links
Discussion
SuperApe: Here's a good start, WheatPuppet.
WheatPuppet: Heh. I probably should've done it myself, but, especially in a Wiki format, I have trouble doing completely new things. 
Adding and editing–I do that fine. I'll probably get time this weekend. I'll put up a sticky-note... there. Now I won't forget. Someone keeps stealing my sticky note pads and I don't like it.
WheatPuppet: I'm pretty sure someone (Tarq?) wrote an essay with some overlapping material, but I don't know where it went. Feel free to edit, since I didn't plan out the above very carefully.
SuperApe: This page needs a little love. It's been a while now and I'm not sure if WheatPuppet is coming back to it.
StarWeaver: The main thing I've noticed about the one-on-one maps i've played in UT2004 (The defaults, ECE, CBP, UCMP, 1-on-1-pack) is that most of them seem *too large* for a one on one match. Heck, the single player ladder sends you to several of them for 3- and 4-way matches, and I found the one-on-one challange matches to generally be pretty boring, especially on maps like Roughinery (But then, if I had set things up it would be a 3 or 5 point match and not a 15 for those . . . ) Heck, I run 4-on-4 Team Deathmatch games on Roughinery and Irondust and such with no problem.
SuperApe: I agree. To me they just seem to say, "this map is fast". But I think they are certainly playable with well over two players. Speaking of rambling, the above text is rather block-like and could use a little organization via sections and sub-sections.
Category To Do – Should make look more like the other "Mapping For..." pages, less rant-like.
