Starcraft AI blog

Some special map features and pro maps which display them. The examples are not exhaustive. There are more features and more maps with them!

This post is to point out how much knowledge a comprehensive Brood War bot needs. Every one of these maps calls for special knowledge to exploit the special feature, and often more knowledge to defend against exploitation of the feature. Hand-coding all this knowledge, if anybody ever does it, will be a long process. Gaining the knowlege by machine learning is tough too; that’s a research project. That is probably why, as far as I know, only 1 bot exploits 1 of these features—see “cliffable natural” below. The other map features are virgin ground.

I’m in favor of tournament organizers incorporating more maps with special features, as long as ignorant bots can still play on the maps without gross blunders. It will encourage bot authors to work on the hard problems. On the other hand, some of these maps are totally unplayable by current bots, which would be unfair to authors who can’t keep up, and makes year-over-year comparisons difficult.

• cliffable natural - Lost Temple, Tau Cross
The natural can be attacked from above the cliff using drop. I’ve seen ICEbot take advantage on Tau Cross by dropping tanks on the cliff. I haven’t seen any other bot exploit the feature. Benzene has a similar feature: Tanks can be dropped outside the neutral buildings blocking the rear entrance, where they are in range of the natural mineral line and reachable by ground only by a long path (I’ve seen ICE do that too). No bot appears to know how to defend the cliff (use air units, or counterdrop, or place tanks below and do something to gain vision, such as float a building).

• base exposed from outside - Jade, Moon Glaive
The edge of the main can be attacked from outside by ranged units over a barrier, without the need to bring an air unit or scan for vision. A bot with the right attack and defense skills would have an advantage. It is rare to see bots do that, and I’ve never seen one appear to intentionally seek an attack from outside.

• back doors - Destination, Heartbreak Ridge
Your base has a rear entrance which the enemy can attack through with extra effort. On Destination, by a nearby mineral block that is easy to monitor. On Heartbreak Ridge, by a more distant mineral block. I have not seen any bot appear to intentionally take advantage of the rear entrances. Another map with a rear entrance is Bifrost, where nothing blocks the rear entrance but the path to reach it is long.

• openable central paths - Detonation, Monty Hall
On Detonation, you can take a long path to the enemy, or you can mine out blocking minerals and take a direct path. Each side has a row of minerals (30 minerals per patch) that they can mine out to reach the center of the map. On Monty Hall, you have to mine out minerals to get a ground army to the enemy base at all, and there is a choice of 3 paths. Another example map is Arkanoid.

• narrow entrances - 815, Blue Storm
Only small units can pass. 815 has a narrow ramp from the main; a dragoon or lurker or tank cannot go up or down. Blue Storm has a narrow entrance toward the center, and a wide entrance around the side with a longer path.

• passable blocks - Gold Rush, Outsider, Plasma
Blocks which can be passed by pushing units through the minerals, or by mineral walking through. Generally, a player must do that to have a good chance. On Outsider, some of the mineral lines can be mined from either side, so there is a choice of where to place your base.

• assimilator blocks - Gold Rush, Troy
Paths with double assimilators. Destroying the assimilators closes the path (except to ghosts, the narrowest unit).

• no natural gas - Nostalgia, Korhal of Ceres
No vespene geyser in the natural expansion. Without a safe second gas, strategies are different. Korhal of Ceres includes other odd features, such as 2 entrances into the main.

• neutral spells - Persona, Triathlon
Persona has permanent dark swarm spells cast over ramps and expansion mineral lines. Triathlon has neutral arbiters which cloak neutral zerg eggs which block the path to expansion bases (among other features).

• maps with islands - 815, Namja Iyagi
These are regular maps with many islands. They’re playable by ignorant bots, but a bot with island skills would have an advantage. In the SSCAIT map pool, these maps have 2 islands each: Andromeda, Empire of the Sun, Python.

• semi-island maps - Dream of Balhae, Indian Lament
Each player’s main is an island and the rest of the map is connected. You need to get drop quickly.

• island maps - Charity, Paradoxxx
Strategies are very different from land maps.