What makes a good Chief Engineer in CK3?

Employer has Positions Of Power Perk (Friend) +5, Learning Skill Learning × 2.5 (max 60), Martial Skill Martial × 1.5 (max 60), Strategist +15 and Engineered For Destruction Perk +15 (the game's aptitude breakdown, patch 1.20.0.3).

What does the Chief Engineer give?

Terrible: Men-at-Arms Siege Weapon Effectiveness +10%, Daily Siege Progress +10%; Poor: Men-at-Arms Siege Weapon Effectiveness +15%, Daily Siege Progress +15%; Average: Men-at-Arms Siege Weapon Effectiveness +25%, Daily Siege Progress +20%; Good: Men-at-Arms Siege Weapon Effectiveness +40%, Daily Siege Progress +25%; Excellent: Men-at-Arms Siege Weapon Effectiveness +66%, Daily Siege Progress +33%.

Camp officers (landless adventurers)

Chief Engineer

Roads to Power

Chief Engineer is a camp officer in Crusader Kings III; its aptitude rests on Learning. At excellent aptitude it gives Men-at-Arms Siege Weapon Effectiveness +66%, Daily Siege Progress +33%. Aptitude also comes from Employer has Positions Of Power Perk (Friend) (+5), Strategist (+15) and Engineered For Destruction Perk (+15). It needs Roads to Power. Patch 1.20.0.3, from game/common/court_positions/types/00_camp_officers.txt.

Quick answers (2)

What makes a good Chief Engineer in CK3?: Employer has Positions Of Power Perk (Friend) +5, Learning Skill Learning × 2.5 (max 60), Martial Skill Martial × 1.5 (max 60), Strategist +15 and Engineered For Destruction Perk +15 (the game's aptitude breakdown, patch 1.20.0.3).
What does the Chief Engineer give?: Terrible: Men-at-Arms Siege Weapon Effectiveness +10%, Daily Siege Progress +10%; Poor: Men-at-Arms Siege Weapon Effectiveness +15%, Daily Siege Progress +15%; Average: Men-at-Arms Siege Weapon Effectiveness +25%, Daily Siege Progress +20%; Good: Men-at-Arms Siege Weapon Effectiveness +40%, Daily Siege Progress +25%; Excellent: Men-at-Arms Siege Weapon Effectiveness +66%, Daily Siege Progress +33%.

The Chief Engineer is responsible for all tasks requiring a knowledge of mechanisms and machinery. They build and repair siege weapons, and instruct the men in their use.

What it gives you, by aptitude

The holder's aptitude (see below) sets the level: levels start at 20, 40, 60, 80.

Terriblebelow 20
- Men-at-Arms Siege Weapon Effectiveness+10%
- Daily Siege Progress+10%
Poor20+
- Men-at-Arms Siege Weapon Effectiveness+15%
- Daily Siege Progress+15%
Average40+
- Men-at-Arms Siege Weapon Effectiveness+25%
- Daily Siege Progress+20%
Good60+
- Men-at-Arms Siege Weapon Effectiveness+40%
- Daily Siege Progress+25%
Excellent80+
- Men-at-Arms Siege Weapon Effectiveness+66%
- Daily Siege Progress+33%

What makes a good Chief Engineer

The game's own aptitude breakdown for this position — every part it adds up:

Part	Aptitude
Employer has Positions Of Power Perk (Friend)	+5
Learning Skill	Learning × 2.5 (max 60)
Martial Skill	Martial × 1.5 (max 60)
Strategist	+15
Engineered For Destruction Perk	+15

The holder gets

Prestige+0.1/month

Who may hire it (valid_position) (10 lines of game script)

custom_tooltip = {
	text = landless_government_tt
	government_has_flag = government_is_landless_adventurer
}
custom_tooltip = {
	text = chief_engineer_camp_officer_parameter_tt
	domicile ?= {
		has_domicile_parameter = camp_unlocks_chief_engineer_officer
	}
}

As written in game/common/court_positions/types/00_camp_officers.txt.

Who may hold it (valid_character) (3 lines of game script)

valid_camp_officer_trigger = {
	OFFICER = chief_engineer
}

As written in game/common/court_positions/types/00_camp_officers.txt.

Shown when (is_shown) (5 lines of game script)

has_ep3_dlc_trigger = yes
custom_tooltip = {
	text = landless_government_tt
	government_has_flag = government_is_landless_adventurer
}

As written in game/common/court_positions/types/00_camp_officers.txt.

Source: game/common/court_positions/types/00_camp_officers.txt, common/court_positions/tasks, common/script_values and the English localisation, Crusader Kings III 1.20.0.3. Salary is the base before the realm-size and cultural-era multipliers.