Game concept · Advanced Activities
Prize
The game also links it as Prizes.
From the game's encyclopedia
Prizes are Artifacts awarded to the victors of Grand Tournament Contests with a single winner.
The quality of the Prize depends on the options chosen by the Activity Host and the Era.
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.
Prize is an entry of Crusader Kings III's in-game encyclopedia (Advanced Activities). The game explains it: "Prizes are Artifacts awarded to the victors of Grand Tournament Contests with a single winner." It is part of Grand Activity. The game also links it as Prizes. Patch 1.20.1.2, from game/common/game_concepts/04_ep2_game_concepts.txt and game/localization/english/game_concepts_l_english.yml.
Source: game/common/game_concepts/04_ep2_game_concepts.txt, game/localization/english/game_concepts_l_english.yml and the English localisation, Crusader Kings III 1.20.1.2.