Here's how: Infestors! If there are P and T on the map, and you begin as Zerg, you can legitimately infest a probe and an SCV, build a Nexus and CC of your own (they get your own color), and from there you don't even need infestors and neural parasite anymore. Your legit new Nexus and CC just pump out more probes and SCVs from your own color, and you get to build the full armies, units and structures, with the full complexity and arsenal of all the 3 races at once, under the same color, and use them together - not as allies, but as just your own inter-racial army.
What does that mean?
- workers of any race can mine for any type of main base; including MULEs for hatchery or nexus
- you can use any race extractor for any race base and get it mined by any race workers heterogeneously; eg: nexus with zerg extractor and terran rafinery, mined by probes, scvs and drones, while also using MULEs on the minerals
- dropships of any race can transport any races: medivacs, ovies and warp prisms can load anything
- food supplies are shared, that means building a pylon makes more food for hatching ultralisks, and also when you quickly need food to mass produce Void Rays, you can use the Terran double supply depot, which is called instantly using energy from Orbital commands
- medivacs can heal your bio-air Z units; so they DO heal air, after all..
- Queens can heal your zealots and marines; imagine them spewing that acid.. oh, well..
- SCVs can repair all Protoss non-bio units, including air units
- Mothership and Nydus network can recall and teleport terrans across the map
- Mothership can provide invisibility to Zerg and Terran units such as invisible hydras, or invisible thors..
- Vortex Nuke: probably the coolest thing in the whole game; while mothership freezes a whole group of enemies in the vortex, a nuke comes to welcome them just when they reappear back from the black hole, so they can't escape the bomb
And finally - 4 motherships with just 1 Protoss player. Answer: it's PZvZZ, having 3 different zerg players means each one can infest protoss and build army of their own color, eventually getting 4 motherships on the map (counting one from the original P) in a 2v2 game with just one P player. Who said it's impossible.
Here're some demos (a bit laggy and tedious, but nevertheless), the full army is seen in part 2:
[ame="http://www.youtube.com/watch?v=79IYKbFaemU&feature=PlayList&p=D1F2BA7C8A4A5690&playnext_from=PL&index=0&playnext=1"]YouTube- Z T P - Part 1 of 3[/ame]
P.S. You get some funny sound effects like for example Nexus trying to chrono boost before its ready saying "Not enough energy" with the creepy zerg voice, while at the same time probes and SCVs use their own voice. I also noticed that around base of some race, an inter-racial group of workers uses the voice of the race of the base - eg: near CC a group of probes, scvs and drones will use the scv sounds, but near nexus they will use the probe sounds. ^^
