Game concept · Advanced Activities
Contest Round
The game also links it as Contest Rounds.
From the game's encyclopedia
Knock-Out Contests determine a winner by pairing all Qualifying Contestants against each other in knock-out bouts until only one remains.
There are three rounds: quarter-finals, semi-finals, and the final.
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.
Contest Round is an entry of Crusader Kings III's in-game encyclopedia (Advanced Activities). The game explains it: "Knock-Out Contests determine a winner by pairing all Qualifying Contestants against each other in knock-out bouts until only one remains." It is part of grand_activities. The game also links it as Contest Rounds. 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.