Game concept · The Fate of Iberia
Border Raid
The game also links it as Border Raiding, Border Raids.
From the game's encyclopedia
This is a special type of War available between Involved Rulers of the Iberian Struggle where the attacker aims to Siege a specific enemy County bordering their Realm.
The War Leader gains Gold for capturing the War Target, which will lose Development and Control. Buildings may also be destroyed, yielding more Gold, the chance increasing with Development and Siege Army size.
War Score will be gained rapidly by the attacker upon Occupying the War Target.
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.
Border Raid is an entry of Crusader Kings III's in-game encyclopedia (The Fate of Iberia). The game explains it: "This is a special type of War available between Involved Rulers of the Iberian Struggle where the attacker aims to Siege a specific enemy County bordering their Realm." The game also links it as Border Raiding and Border Raids. Patch 1.20.1.2, from game/common/game_concepts/03_fp2_game_concepts.txt and game/localization/english/game_concepts_l_english.yml.
Source: game/common/game_concepts/03_fp2_game_concepts.txt, game/localization/english/game_concepts_l_english.yml and the English localisation, Crusader Kings III 1.20.1.2.