Game concept
Trait Experience
From the game's encyclopedia
Experience is required in order to move further down a Trait Path and change the bonuses the Trait provides.
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.
Trait Experience is an entry of Crusader Kings III's in-game encyclopedia. The game explains it: "Experience is required in order to move further down a Trait Path and change the bonuses the Trait provides." It is part of Trait Path. Patch 1.20.1.2, from game/common/game_concepts/00_game_concepts.txt and game/localization/english/game_concepts_l_english.yml.
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.