- Short distance between natural and third. Ex: Cloud Kingdom, Entombed Valley
- The ability to bounce back between the natural and third without running into enemy units. Ex: Cloud Kingdom, Entombed Valley, Daybreak, Not Korhal Compound
- Chokes and/or ramps to the entrances of the natural/third. Ex: Cloud Kingdom, Entombed Valley
- Small surface area to cover with forcefields to all bases. Ex: Not Antiga Shipyards, Not Dual Sight
- Large rush distance to opponent's natural/third. Ex: Metropolis, Whirlwind, Not Antiga Shipyards
Impossible for Protoss to take a passive third
- Korhal Compound: Distance between natural and third is too long,
- Dual Sight: Too much surface area to cover between both natural and third.
Really really hard for Protoss to take a passive third
- Antiga Shipyards: Too much surface area to cover between natural and third, needs about 7 forcefields to cover the whole thing
- Shakuras Plateau: Too much surface area to cover between natural and tucked third, need a ton of forcefields. You can't bounce back between natural and opposite natural, should you choose to take that as your third.
Acceptable Standard Maps-not too easy, not too hard
- Daybreak: large choke to third and large ramp at natural make it somewhat difficult
- Cloud Kingdom: two paths to the third make it somewhat difficult
- Metropolis: large rush distance helps deter roach attacks greatly
- Whirlwind: the natural/third design is actually bad for vs roach attacks, but the size of the maps counteracts this greatly
- Atlantis Spaceship
Probably too easy to take a third
- Entombed Valley: all PvZs are generally very passive here, has almost all the features Protoss could want to take an easy third. Still, a somewhat acceptable map
- Calm Before The Storm: way too easy to get both the natural and third
If a map is too easy for Protoss to take a third, you'll end up with overly passive games. If it's too hard, Protoss will always 2 base all-in. You'll also notice that most of the maps that are too easy/hard are being phased out, while all of the acceptable standard maps are the ones we currently use. In the future, at least until HotS comes out to change things, it's probably better to make maps that are at least somewhat easy to take a third on. That's all. Good day!