Starcraft – Why are there neutral supply depots in some Starcraft 2 maps

• Most of the advice to stop Nydus worms applies in general. First of all, you should be keeping an eye on your base no matter which race you are facing, and regardless of whether or not you have scouted a Nydus Network in the Zerg's base. All races have ways of getting units into the back of your base without going up the ramp. Medivacs, proxy pylons, overlords with ventral sacs, warp prisms, blink stalkers, colossi, reapers, etc, not to mention pretty much any air unit.

• Denying vision to the zerg player by harassing overlords should be done in general, not just to stop worms.

• To help detect the nydus worm (and all other threats mentioned in previous bullet), spread buildings out in your base, so you have vision everywhere. Terrans can spread supply depots, protoss have pylons, and zerg have creep tumours, or overlords to spread around.

• Learn the sound a nydus worm makes when it completes. Sadly for us zerg players, the nydus worm announces itself to all players with a loud scream, similar to how everyone hears "nuke launch detected". On the plus side (for us), it only screams as it is finishing. This won't help you stop the worm, but it will alert you that you should be looking for the worm to make sure it's not in your base, or if it is, mobilize some troops to defend.

• In team games, consider using the team colors option for the minimap, so your units are green and your opponents are red. This will make the nydus worm stand out in your minimap more than if you are orange and your opponent is yellow, or some other combo of similar colors.

• Worms don't have a lot of HP, even when they complete. When they are building, a handful of units can kill it before it completes. I just did a quick test; 3 marines starting to shoot as soon as the worm reaches 50% done can kill it just after it finishes, enough time for only a few units to get out.

• Remember that each worm costs the zerg player 100 minerals and 100 precious gas. Each time you kill one before it completes, the zerg is behind on resources. They can also only be building one at a time. (specifically, one per Nydus Network)

When you play online you don't have much control over the map you will play. You can veto some maps off but in the end, it doesn't really matter whether the map is really played a lot or not, just your personal preferences.

In tournament, a popular map choosing technique is that the first map is decided either randomly, or every 1v1 starts on the same map. In Starcraft 1 Lost Temple has been chosen like this a lot in the early days (later on, it has been judge a little imbalanced because blocking the ramp gave the terran players a slight advantage).

After the first map, either the winning (rarely) or the losing (much more often) player would decide which map is to be the next. I'd say that most of the time, a 4 players map for a 1v1 is prefered since it gives each player much more territory to expand. Sometimes, they will choose "Steppes of War" in a "I want to rush you" fashion since it is the map where the spawning spots are the closest of the whole map pool.

So, on Battle.net, the maps are random so personal preferences don't impact the game much. Some maps are better for some races or some strategies (large choke points = harder to block = easier to rush).