The 4 Gates is a very aggressive Protoss strategy once you have your first base. Widely used in PvP (Protoss Vs Protoss) and can also be used in PvZ and PvT, although it is often less effective. The 4 Gates lets you expand very quickly, so you can quickly put pressure on your opponent using a Pylon near the enemy base, which makes your attack more effective. This rush allows you to attack your opponent's ramp and warp units over the ramp by having vision (which is possible when you attack). However you will need one or more Pylons for this move, placed at the bottom of the enemy ramp, so that you can warp your units.
This strategy is an all in opening and it will be very difficult to begin a transition to the mid-game. So you will have to play everything with this attack(s). In fact, you will have very few Probes and you will be very focused on the micro-management of your units during the attack. For information, to optimise your 4 Gates, you will only have 16 Probes for the minerals as well as 3 for Gas, so a total of 19 Probes to set up this strategy.
This Build Order is based heavily on the placement of your Pylon(s) near the enemy base. Your attack must be timed and it is important to avoid warping your units home. You would lose a lot of time and this is not the goal when you want to set up a Rush. So you must keep in mind that the success of your strategy will be based on the placement of your Pylons. If you are unable to place your Pylon near the enemy base then your opponent will have much less trouble countering your attack.
Pylon
Gateway + Scouting
Assimilator
Cybernetics Core + Production of a Zealot
Production of a Stalker + Start researching WarpGate
Stop the production of Probes at 16 in your mineral line + 3 in Gas
At 50% Research, build your 3 additional Gateways
At 50% Research, build a Proxy Pylon
** the numbers 9/12/14/... refer to your population in the game **
Don't forget to continue your production of Probes while you do your build order.
Note that it is very important not to miss the timing when it comes to placing your proxy Pylon. Similarly, you should only Chrono boost the production of your Probes TWICE, the rest of your Chrono Boost will be used to boost your Warpgate research. This will make a total of 4 Chrono Boosts. With perfect timing, you get to start 5 Chrono Boosts, but by using only one boost on your Probes. Keep in mind that you should not stop Chrono Boosting your Cybernetics Core throughout the research.
Your Gateways and Warpgate research should be perfectly timed. This means you will have to be very careful with the timing when building your Gateways (50% of the research time for a Warpgate).
Although it is best if you can hide your 4 Gates, they are often easy to detect. Don't hesitate to place your Gateways before rather than delay building them.
