Dae'Uhl

The Dae'Uhl, or "Great Stewardship", was one of the core principles of Protoss society.

Background
The origins of the Dae'Uhl can be found in the coming of the Xel'Naga. Despite their good intentions, the race's nurturing for the Protoss led them into the Aeon of Strife. After emerging from this period and expanding beyond Aiur, the Protoss took it upon themselves to follow the traditions of the Xel'Naga; protecting and safeguarding "lesser races" under their protection. Unlike the Xel'Naga however, the Protoss would not directly interfere, an edict that was likely enforced in the aftermath of the Kalathi Intercession.

Exceptions...
The Protoss observed the coming of humanity to the Koprulu Sector, the Dae'Uhl putting the Terrans under the guard of the Firstborn. If not for this edict, it is nebulous whether humans may have been able to survive in the "New World", the Protoss concerned as to how quickly the Terrans were able to access natural resources, paying little heed to effects on the natural enviroment. Although the Dae'Uhl forbid the Protoss from direct action, the coming of the Zerg led to a relaxation of the tennants, thus allowing the Protoss to steralize infested Terran worlds, regardless of any humans on them. Although Tassadar strove to uphold the Dae'Uhl's principals (prompted by his own moral center), the Conclave had essentially abandoned them.

Modern Day
In the modern day, with the Protoss concentrated on Shakuras and their military might shatterred, it is extremely unlikely that the Dae'Uhl or any similar code features in their society.