- 13 - Gateway
14 - Assimilator
17 - Cyber
19 - Assimilator
23 - Stalker (You want to keep the stalker relatively close to your base unless you kill the scouting scv. If you scout tech lab just leave it in your base.)
23 - Warp gate
26 - Robotics Facility (Build as fast as you can as long as your stalker is almost done and they have not scouted you. If not prolong until you get the scv out.)
28 - Sentry
30 - Nexus (Only if you feel they have expanded themselves. For example if they don't have gas they are more then likely expanding. If you kill the scouting scv and you push out with your stalker and see a bunker throw down the nexus you can always cancel.)
30/31 - Robotics Bay
32 - Warp Prism
32 - Pylon ( YOU CAN NOT FORGET THIS PYLON)
------ You should now have full chrono on your nexus and your minerals/gas should be around 400 - 300 if done perfectly. (The colossus will finish first. Save a extra chrono for thermal lance/gravitic drive)
40/41 - Colossus
41 - Gravitic Drive
45 2 Gateways
-Thermal Lance whenever you can afford (Use all chrono on forth until its done)
50 - Observer (Park the observer right outside the ramp to see if they are moving out, if they are you need to try and take down the army as it leaves. If you see viking get out of there unless you are very skilled with your warp prism micro and observer)
----- You should be using chrono boost on probes up until your robotics facility is down, once it is down keep saving chrono until you can chrono the colossus/gravitic drive.
----- You should park your warp prism in the path where possible drops/banshees come, simply because if it was say a helion drop you can pull your probes to block the path of which the helions drop and kill them all off before they do their damage. Do not forget that you can use your warp prism to pick up damaged units/probes.
----- If they 2 rax you delay your expansion if you have to lay down a couple gateways. If they are agressive with the 2 rax build a extra sentry and delay your gravitic drive. You should have about 3 ff set and your colossus will almost be done by then.
----- If they 1-1-1 try to focus down marines/scv's the more marines you pick off the longer you delay their attack. Also throw down 3 gateways and skip the expansion unless you believe you can hold it off with the expansion. The warp prism is extremely good vs 1-1-1 for instance.... You can drop a single zealot and all tank fire will go on it while you engage with the rest of your army, from there you drop 3 more zealots on tanks. Once you become very good with this style of play holding off 1-1-1 is extremely easy. However if they start making a lot of vikings you will need to stop producing colossus especially if they have a raven simply because if they make vikings they are going to have less banshee support which also in return makes it so the raven is less valuable and a heavier zealot immortal army will be much stronger.
If you have any questions just post and I might reply to them.