Psi is a protoss gameplay counter limiting the size of a protoss force. Every constructed unit costs psi, and more psi can be generated by warping in pylons, up to a maximum value of 200. New units can be produced so long as the cumulative psi of all active units does not exceed the number of available psi.
In strategy discussions, psi levels may be denoted as x/y, where x is the psi used, and y is the total available psi. Unit costs may be denoted as x/y/z, where x is the cost in minerals, y is the cost in gas, and z is how much psi is used.
Terran supply and zerg control serve the same purpose.
StarCraft[]
The 200 point supply limit may be exceeded through the dark archon's mind control ability; this is legal in competitive scenarios, and no new units may be built until consumption falls back below 200. The counters for supply, psi, and control are also kept separately; a 600-point force may be constructed by capturing SCVs and drones and building up the non-protoss tech trees.
Building/Unit | |
---|---|
9 | Nexus |
8 | Pylon |
Units | |
---|---|
1 | |
2 | |
3 | Scout |
4 | |
6 | Carrier |
StarCraft II[]
Building/Unit | |
---|---|
15 | Nexus (LotV) |
10 | Nexus (WoL/HotS) |
8 | Pylon |
Units | |
---|---|
1 | |
2 | |
3 | |
4 |
|
5 |
|
6 | |
8 | Mothership |