Engineer archetype

Not every hero is a killer. The Engineer is a non-combat archetype whose whole job is improving faction economy. Their primary loop is not sector-patrol-and-fight but travel-to-station / apply-buff / move-on.

Mechanically, the Engineer is a modifier of external state — they don’t shoot things; they change how much production a friendly station outputs per hour. It’s the mod’s first non-combat gameplay loop, and it turns out to be one of the mod’s cleanest interactions with vanilla X4’s economy.

Coverage

6 templates across the “production-heavy faction” set: Argon, Paranid, Teladi, Split, Terran, Boron
Also spawnable for their sub-factions (Antigone, Holy Order, Hatikvah, Ministry, Free Split, Kaori — with sub-faction identity inherited from parent-race template)
Not for pirates / Xenon / Kha’ak — they don’t have a production network to service. Also not for coordinators-only factions (small).
Engineer slot is separate from admiral slot. Formula: engineer_slots = 1 + floor(stations_owned / 5), capped at 10 per faction.

Playstyle — the travelling mechanic

Engineers are mobile but non-combat. Their flagship is an M-class miner ship (visually the mining rig loadout — mining tools protruding, a working, industrial silhouette). Very small S-fighter escort (0-4 depending on rank, self-defence only).

They fly:

From station to station within their own faction’s territory only (never through hostile / neutral space)
To the highest-production own-faction station that isn’t currently buffed and isn’t claimed by another engineer
Apply a temporary production efficiency buff, then move to the next target
Return to HQ for RP replenishment when they run low

They never engage in combat willingly. If attacked, they route through the retreat cascade — MoveGeneric back to a safe own-faction sector, resume ops after cooldown.

Fleet composition per star rank

Engineers do not swap flagships across star ranks. The M miner is their identity.

★	Flagship	Escort
★	M miner (race-specific)	0× S fighters
★★	M miner	1× S fighter
★★★	M miner	2× S fighters
★★★★	M miner	4× S fighters

The escort is purely for personal defence during travel. Engineers are visibly not warfleets — a Teladi player will see the Engineer’s Teladi mining rig outfit + a Teladi fighter pair, and know at a glance “that’s the engineer, not a war party”.

Decision cascade

Engineer decision loop is simpler than admiral / coordinator — four decisions in priority order:

flowchart TD
  Start[HMW tick] --> Q1{state ==<br/>lost_flagship?}
  Q1 -- yes --> R1[retreat<br/>no order]
  Q1 -- no --> Q2{RP < service_cost<br/>OR hull damaged?}
  Q2 -- yes --> R2[replenish<br/>Move to HQ<br/>RP tick + repair]
  Q2 -- no --> Q3{Target station<br/>available AND<br/>reachable?}
  Q3 -- yes --> R3[travel<br/>Move to target station]
  Q3 -- no --> R4[idle<br/>Patrol HQ sector]

Priority	Decision	Effect
1	lost_flagship / retreat	Rebuild via Recovery Points, same as other archetypes
2	replenish	Return to HQ station when RP insufficient for another service action, or when hull damaged. RP tick continues; hull repairs via 100 RP if damaged
3	travel (`Move to station`)	Fly to the picked target station (highest-production, own-faction, not yet buffed, not claimed by another engineer)
4	idle (`Patrol HQ`)	Fallback when no eligible target — patrol home sector waiting for a new station to become available

Also implicitly: service_station action fires at target arrival (not a separate decision — it’s the action executed on arrival).

The buff — how it actually works

X4 9.x doesn’t expose a writable “production efficiency” property. So the Engineer’s buff is simulated:

On service, the mod sets $module_buff_active = true on the target station’s registry entry, records $buff_pct (based on Engineer’s ★) and $buff_until (based on ★-duration table)
Every 15 game-minutes, a global worker iterates buffed stations. For each buffed module producing output:
- Reads the module’s expected vanilla production_rate (from module recipe × current inputs)
- Calls add_wares to inject production_rate × buff_pct × interval additional output into the station’s cargo
Inputs are NOT deducted — the semantic is “the engineer makes inputs go further”

No API for cross-faction: Engineers only buff own-faction stations. A Teladi engineer never buffs an Argon station.

Buff tiers per star rank

★	Buff pct	Duration	Feel
★	+20% efficiency	6 game-hours	Gentle steady bump
★★	+30%	9 hours	Noticeable difference
★★★	+50%	12 hours	Impactful — a hero engineer’s stations pump
★★★★	+80%	24 hours	Endgame — Teladi Ministry with two ★★★★ engineers has 20-40% of their production silently overclocked

Service cost: 100 RP per action. Per-engineer cooldown: 60 game-minutes (can’t spam a single hero across multiple stations back-to-back).

Station claiming (multi-engineer race resolution)

If a faction has multiple Engineers (large factions with big station networks), they race to claim targets:

Each station has $mlog_eng_claim_by (which engineer claimed it) + $mlog_eng_claim_until (30 min expiry) fields
When an Engineer picks a target station via HeroManager, they atomically write the claim
Other Engineers filter out claimed stations from their picker
On service action or claim expiry (30 min), the claim clears
On arrival, the Engineer checks the claim is still theirs — if another engineer beat them there and already buffed, the race is lost and the Engineer goes back to idle

Result: multi-engineer factions naturally spread across station networks without conflict.

Stacking rules

Engineer buffs do NOT stack with each other. Buffed stations are excluded from the picker. If Argon has two ★★★ engineers, they buff two different stations; never the same one.
Engineer buffs DO stack with:
- Vanilla workforce production bonus
- DA-Eco DA Wares boosts (if DA-Eco is installed — but Heroes doesn’t require it)
- Any other vanilla buff
Result: a station being both workforce-buffed AND Engineer-buffed produces base × (1 + workforce_bonus) × (1 + engineer_pct) — multiplicative stacking with vanilla systems.

XP economy

Engineers gain XP differently from combat archetypes. Their XP source:

+1 XP per production module of the buffed station, credited on the service action

Practical numbers: a mid-tier Teladi production station has ~6 production modules → +6 XP per service. At 1 service per 60 min, that’s ~6 XP/hour. To reach ★★★ (1000 XP), an Engineer needs ~166 hours of active service — very slow, realistic-feeling career.

No combat XP source (Engineers never kill anything).

Behaviour example — a Teladi Engineer

Daria Sokolova, Chief Engineer of Argon Federation industrial corridor. ★★, 200 XP, 210,000 cr in the wallet.

HeroManager tick: her flagship is docked at Argon Prime shipyard (HQ). RP = 3/200, and the last service was 40 min ago — not enough RP yet for the next 100 RP action.
Decision: replenish — she stays at HQ, RP tick continues. Next tick, RP is 65/200, still not enough.
30 min later, RP hits 100. Decision: travel — the picker finds “The Reach” sector, ARG Plasma Conductor Factory I. Not yet buffed, not claimed. Distance: 4 gate hops all through Argon-owned space.
She undocks, flies to The Reach, docks at the plasma conductor factory.
Service action: applies +24% efficiency buff (30% base for ★★, but her Master Technician perk is +20% relative → 30% × 1.2 = 36%… actually 30% + 20% relative = 36%, though the exact math depends on stacking) for 9 game-hours. RP -100. XP +11 (station has 11 production modules).
She waits at the plasma conductor factory until the service cooldown wears off (30 min with Efficient Service perk, else 60 min).
Next HeroManager tick: replenish → back to Argon Prime, or if RP not too low, immediately travel to the next-highest priority station.
Over 9 game-hours, the ARG plasma conductor factory produces ~24% more plasma conductors than baseline. Argon shipbuilding gets faster. The player never sees this in a notification; they see it in stronger Argon fleets 10 hours later.

Death of an Engineer

Engineers can be KIA’d like any archetype. Same d100 roll on flagship destruction: 20% KIA / 60% wounded / 20% unscathed at defaults.

Active buffs survive the Engineer’s death. A station buffed 4 hours ago continues to receive add_wares for the remaining 5+ hours regardless of who buffed it. The buff is on the station, not on the Engineer.

On KIA, standard lineage vacancy (120 game-minutes) → new clone spawns with the Engineer’s inherited perks.

What’s next

Engineer visualization overlay — currently the buffed stations + active buff timers are visible only in the Engineer’s detail page. A future overlay may show the whole faction’s buffed-station map.
Cross-service — Engineers currently only buff production stations. Future: buff shipyards (build speed +X%), buff wharves (equipment stock +Y%), buff trading stations (ware turnover +Z%). Cargo-injection extends naturally.
Enemy sabotage (concept) — a “reverse engineer” could apply negative production buffs to enemy stations. Different archetype, same primitive.

Admiral archetype — the combat-focused mobile archetype
Coordinator archetype — the immobile HQ-based archetype
Perks system — Master Technician (+20% buff potency), Long Lasting Buff (+50% duration), Efficient Service (30 min cooldown), Reduced Cost (50 RP service) are the engineer-specific perks