Game concept

Demand Conversion

The game also links it as Demanding Conversion.

From the game's encyclopedia

Rulers who have a subject of another Faith may Demand Conversion to change their subject's Faith to their own. The Ruler's Learning skill and the subject's Opinion of their liege are major factors in determining if the subject accepts the demand, or refuses it.

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.

Demand Conversion is an entry of Crusader Kings III's in-game encyclopedia. The game explains it: "Rulers who have a subject of another Faith may Demand Conversion to change their subject's Faith to their own." It covers Refuse Conversion. The game also links it as Demanding Conversion. Patch 1.20.1.2, from game/common/game_concepts/00_game_concepts.txt and game/localization/english/game_concepts_l_english.yml.

for a guide, post or blog

Source: game/common/game_concepts/00_game_concepts.txt, game/localization/english/game_concepts_l_english.yml and the English localisation, Crusader Kings III 1.20.1.2.