Game concept
Duel Edge Penalty
From the game's encyclopedia
As Characters Duel, they may be afflicted with temporary disadvantage, often due to their opponent severely hurting or intimidating them. This decreases their Prowess for the duration of the current bout, but is regained immediately after.
The opposite of Duel Edge Penalty is Duel Edge Bonus.
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.
Duel Edge Penalty is an entry of Crusader Kings III's in-game encyclopedia. The game explains it: "As Characters Duel, they may be afflicted with temporary disadvantage, often due to their opponent severely hurting or intimidating them." It is part of Single Combat. 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.