If you are using the protoss, Dark Templar Rush can be a very effective and useful protoss strategy. First, build a tower with your second probe that will spawn in the nexus. Use that same probe to scout out the enemy and harass the workers with Zealots. The goal of this Protoss strategy is to go after the resource collectors and cut off your opponents’ resources. This is essential to correctly execute the Dark Templar Rush.
Chrono immediately boosts into the nexus and micro his harass probe. Your goal here is to build as many structures as your resources allow. You’ll also want to keep harassing your opponent, which requires a bit of micromanaging. If possible, build a pylon on your opponents’ natural expansion to prevent units from escaping. Also be prepared for a reaper/zealot race that will inevitably happen. Build a proxy pylon near your opponents base, but keep it HIDDEN and don’t use it (yet).
Once your opponents figure out what you’re doing, he’ll come after your base with everything. There are a couple of things you can do. First, you can create a bottleneck at the entrance to your base. Place a zealot at the entrance and maintain positioning to stop any attacks on the front door. You may also want to put a couple of stalkers behind the fans in front. This Protoss strategy prevents your opponent from attacking you en masse. Due to this bottleneck, they must send out the attackers one at a time to give him the upper hand. A second strategy that you can use is that you can build a Dark Templar in your base. This way, if your opponent tries to attack, he will have a nice surprise waiting for him. A third thing you can do is heavily fortify your base with Forge Cannons that will help you block the entrance to your base. Any of these methods can work. Which one you decide to use is really up to you and what you are comfortable with.
Get 2-3 more warp gates so you can focus later. If there are destructible terrain entrances to your base, build a pylon. Don’t attack his army with DTs, go for the structures. If your opponent has supervisors or scan sweep, don’t try to force your way into his base. If you find out that he has one of these two, stop building DTs and move on to something else. Try to get a warp prism to drop the DTs behind your opponents base. The Dark Templar Rush can be a very effective protoss strategy if executed correctly, but be prepared. If your opponent is setting up for a Dark Templar Rush, this Protoss strategy will be extremely difficult to pull off and you should probably abandon it.