Sim City is now more important than ever for Protoss with changing Photon Overcharge from being cast on the Nexus to Pylons. While this can be daunting, a very reliable way to improve your performance in PvT is to standardize your building and army placement on a per map basis so that you aren’t frantically scrambling during a game to get into a defensive posture versus an aggressive Terran.
This is probably the most vital part, but easiest to explain its effectiveness. I always tell people that you should build your first two Pylons in your main base, and the next 3 in your natural, one more in your main base, and then a 4th in your natural. The first 2 in your main base should go next to your Assimilators to build a Reaper wall to help defend against Reapers while also giving adequate coverage of your mineral line with Photon Overcharge. Your next 2 Pylons should go in front of your natural to defend against early game pushes with Photon Overcharge, and your 5th Pylon should go behind your natural’s mineral line to cover the mineral line from drop harass.
Your 6th Pylon should go somewhere in between your main and natural for additional building placement, while you 7th Pylon should join your 3rd and 4th Pylons at the front of your natural for a total of 3 to help defend with Photon Overcharge. The rest of your Pylons should be split between around your third for defensive warp-ins and between your main and natural to avoid Artosis Pylons with your production and tech structures.
You want your initial Gateway, Cybernetics Core, Twilight Council, and Robotics Facility built around the 2 initial Pylons in your main to help form a defensive wall around your mineral line. Be careful not to completely close this wall so you can transfer Probes and evacuate them from the Mineral line. The rest of your tech and production structures should be placed between your main and natural since that is the most difficult place to harass your buildings with drops.
Army and Mothership Core Placement
When you are on two base, before building your third, you want to have your army units defending your main and your Mothership Core defending your natural. The reason why earlier when I talked about Pylon placement that you want your 3rd, 4th, 5th, and 7th Pylons at your natural is because Photon Overcharge can defend or delay any frontal push up until that point, while your units may not be able to. They are more suitable to defending drop play in your main since fewer of Terran’s units are involved and thus you can trade more cost efficiently.
Once your third is established, you want to find the most optimal position for your Mothership Core to help defend your natural and third (on maps where your third is below a cliff to your main, the Mothership Core can patrol on that cliff to defend all three). You want to keep some units in the main (6 Stalkers is a good amount since they can 2 shot Medivacs) while keeping the rest of your army positioned well between your main and natural.
When High Templar come into play, you want to keep 2 at each base since they can Feedback Medivacs and Storm units. Then, a quick warp-in or Photon Cannons can help clean up whatever remains of the Terran’s harassing force.
Example Pictures On Frozen Temple