What is the default Generate Families game rule in CK3?

On: Most landed historical characters with no recorded family will have a spouse and up to three children generated for them. This reduces the risk of an early Game Over. (patch 1.20.1.2)

Does changing the Generate Families rule disable achievements?

No: none of its 3 settings carries the flag blocks_achievements in patch 1.20.1.2.

Game rule · Tweaks · Flavor

Generate Families

On · default
On (AI Only)
Off

Generate Families is a game rule in Crusader Kings III (Tweaks and Flavor) with 3 settings: On (the default), On (AI Only) and Off. 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 Generate Families game rule in CK3?: On: Most landed historical characters with no recorded family will have a spouse and up to three children generated for them. This reduces the risk of an early Game Over. (patch 1.20.1.2)
Does changing the Generate Families rule disable achievements?: No: none of its 3 settings carries the flag blocks_achievements in patch 1.20.1.2.

3 settings

On
Default
Most landed historical characters with no recorded family will have a spouse and up to three children generated for them. This reduces the risk of an early Game Over.
The script checks it 2 times, in 2 places
Events 1
- game_rule.1000
On actions (the game's own hooks) 1
- on_game_start_after_lobby
Every has_game_rule = on_generate_families in game/common and game/events, by the top-level object it sits in.
on_generate_families
On (AI Only)
Most landed historical AI characters with no recorded family will have a spouse and up to three children generated for them. This increases the risk of an early Game Over.
The script checks it 3 times, in 3 places
Events 1
- game_rule.1000
Event file 1
- only_ai_if_ai_only_trigger
On actions (the game's own hooks) 1
- on_game_start_after_lobby
Every has_game_rule = on_generate_families_ai_only in game/common and game/events, by the top-level object it sits in.
on_generate_families_ai_only
Off
Landed historical characters with no recorded family will NOT have a family generated for them. This increases the risk of an early Game Over.
off_generate_families

Source: game/common/game_rules/00_game_rules.txt line 1012 (key generate_families), modifiers from game/common/modifiers, names from the English localisation; Crusader Kings III 1.20.1.2.