Game concept
Contract Tier
The game also links it as Tier.
From the game's encyclopedia
Contract Tier is reflective of the Tier of the Contractor.
Barons and Counts are one star, Dukes are two stars, and Kings and Emperors are three stars.
Contractors won't offer work to Adventurers with insufficient Level of Fame for their Rank. If you're only established, then Kings and Emperors won't even consider you.
The higher the Contract Tier, the higher the pay is scaled to be — though the difficulty of the task is generally also higher.
Personality also affects pay: Greedy Characters will pay under the going rate, Generous or Profligate Characters will pay far over it.
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.
Contract Tier is an entry of Crusader Kings III's in-game encyclopedia. The game explains it: "Contract Tier is reflective of the Tier of the Contractor." The game also links it as Tier. Patch 1.20.1.2, from game/common/game_concepts/07_ep3_game_concepts.txt and game/localization/english/game_concepts_l_english.yml.
Source: game/common/game_concepts/07_ep3_game_concepts.txt, game/localization/english/game_concepts_l_english.yml and the English localisation, Crusader Kings III 1.20.1.2.