What is the default Conquerors: Bonuses game rule in CK3?

Default: Conquerors gain the Conqueror Trait. (patch 1.20.1.2)

Does changing the Conquerors: Bonuses rule disable achievements?

No: none of its 5 settings carries the flag blocks_achievements in patch 1.20.1.2.

Game rule · Difficulty · AI

Conquerors: Bonuses

Default
None
Extreme
Random
Low Random

Conquerors: Bonuses is a game rule in Crusader Kings III (Difficulty and AI) with 5 settings: Default (the default), None, Extreme, Random and Low Random. None of its settings disables achievements. Patch 1.20.1.2, from game/common/game_rules/00_game_rules.txt.

This section as JSON: /raw/game-rules.json

Quick answers (2)

What is the default Conquerors: Bonuses game rule in CK3?: Default: Conquerors gain the Conqueror Trait. (patch 1.20.1.2)
Does changing the Conquerors: Bonuses rule disable achievements?: No: none of its 5 settings carries the flag blocks_achievements in patch 1.20.1.2.

5 settings

Default
Default
Conquerors gain the Conqueror Trait.
The script checks it once, in 1 place
Casus belli 1
- Vassalization
Every has_game_rule = default_conquerors_bonuses in game/common and game/events, by the top-level object it sits in.
default_conquerors_bonuses
None
Conquerors will be much more aggressive, but will gain no special bonuses.
The script checks it 4 times, in 4 places
Events 1
- To Rule the World
Scripted effects 1
- ai_chance_to_become_conqueror_effect
Scripted triggers 1
- ai_should_get_conqueror_bonuses
Story cycles 1
- Conqueror
Every has_game_rule = no_conquerors_bonuses in game/common and game/events, by the top-level object it sits in.
no_conquerors_bonuses
Extreme
Conquerors gain the Conqueror Trait and Scourge of the Gods Modifier.
The script checks it 5 times, in 3 places
Events 1
- To Rule the World
Story cycles 1
- Conqueror
Casus belli 1
- Vassalization
Every has_game_rule = extreme_conquerors_bonuses in game/common and game/events, by the top-level object it sits in.
extreme_conquerors_bonuses
Random
Conquerors gain the Conqueror Trait and have a 5% chance of gaining the Scourge of the Gods Modifier.
The script checks it 2 times, in 2 places
Story cycles 1
- Conqueror
Casus belli 1
- Vassalization
Every has_game_rule = random_conquerors_bonuses in game/common and game/events, by the top-level object it sits in.
random_conquerors_bonuses
Low Random
Conquerors gain the Conqueror Trait and have a 0.5% chance of gaining the Scourge of the Gods Modifier.
The script checks it 2 times, in 2 places
Story cycles 1
- Conqueror
Casus belli 1
- Vassalization
Every has_game_rule = reduced_random_conquerors_bonuses in game/common and game/events, by the top-level object it sits in.
reduced_random_conquerors_bonuses

Source: game/common/game_rules/00_game_rules.txt line 175 (key conquerors_bonuses), modifiers from game/common/modifiers, names from the English localisation; Crusader Kings III 1.20.1.2.