Game concept · All Under Heaven
Prosperity Decree
The game also links it as Prosperity.
From the game's encyclopedia
With the Prosperity Decree, the Mandala Ruler is focused on stimulating and inspiring all Subjects to enact constructive changes.
Efforts are funneled into furthering Development, Buildings, amassing wealth as well as strengthening community via personal relations.
The game's text for patch 1.20.1.2. Words in blue are entries of the encyclopedia: hover one to read it, as in the game.
Prosperity Decree is an entry of Crusader Kings III's in-game encyclopedia (All Under Heaven). The game explains it: "With the Prosperity Decree, the Mandala Ruler is focused on stimulating and inspiring all Subjects to enact constructive changes." It is part of Mandala Decree. The game also links it as Prosperity. Patch 1.20.1.2, from game/common/game_concepts/tgp_game_concepts.txt and game/localization/english/game_concepts_l_english.yml.
Source: game/common/game_concepts/tgp_game_concepts.txt, game/localization/english/game_concepts_l_english.yml and the English localisation, Crusader Kings III 1.20.1.2.