Objectives:
Destroy the heart of the Conclave
Immediately pull your units back to the base. There is a perimeter defense already in place which should turn the attackers back. You’re fighting your fellow Protoss this time, and they’re out for blood. Build up the base defenses a little further by concentrating on unit production and upgrades.
NOTE: You now have access to the observatory, which allows you to create Observers. These are permanently cloaked and reveal large portions of the map with ease. Use them to scout ahead and find enemy troops. It is also wise to send at least one along with a squadron of Scouts, so that they can attack any hidden units.
Build some Dragoons and Reavers to shore up your defenses. The enemy will be throwing them at you, along with Scouts and Carriers. Responding quickly to attacks is very important here. Build up a large force of Zealots, Dragoons and Scouts; you will need them. The key here is a mix of air and group power. The enemy tends to favor ground power.
Put three Probes into a Shuttle and send it to the east as soon as you can. There is a large resource cache here that is relatively (or totally, depending on how quickly you make it there) undefended. Take the position and set up a secondary base. Use this base as an assembly area for your attacks into the northeast territory.
Build at least two Reavers, 12+ Zealots, 12+ Dragoons, 2-4 Observers and 12-24 Scouts. This is your main attack force. Move them
to the northeast, with the Zealots and Reavers in front. Have the Reavers destroy the Photon Cannons at the entrance, then move the Zealots and Scouts in after them. Arbiters should always be your first targets. Their cloaking fields conceal any nearby enemy units. Destroying them will allow you to attack the hidden units.
Clear the area and set up a third base. Like the other two, this one will also need to be heavily fortified. Replace any losses and get ready to move to the next base. The final Conclave base is to the south of your third base. You will need to Shuttle-drop your troops in, which means using Scouts to secure a beach head for the landing. Make sure you have at least 12 Scouts to do this.
You can also build six additional Scouts and send them to attack from the east or west. This will draw some attention away from your main assault force. It will cost a bit in terms of troops and resources, but it may give you the time you need to get your troops on the ground. Once you’ve cleared the outer defenses, allow the ground forces some time to make some headway before you send your Scouts back in. Remember, destroy Arbiters first and attack the Carrier itself instead of the fighters. Keep pushing through the enemy lines until you destroy the Nexus in the far southeast corner.