Apprenticeship

A skilled elf and a novice working side by side at the same craft can form a master-student bond. Over time the apprentice's hands grow surer, their aesthetic drifts toward the master's, and their compositions carry the master's name as a stylistic signature. When the apprentice reaches mastery, the bond resolves -- sometimes in pride, sometimes in resentment.

Overview

Apprenticeship is a one-to-one bond between two elves working the same skill. There is no manual assignment: the simulation matches eligible pairs every 50 ticks based on skill, proximity, and current task. Bonds form silently, deliver their effects continuously while the pair stays close, and resolve at graduation when the student reaches skill 10.

A master can hold at most one active apprentice. A student can have at most one master. Bonds dissolve cleanly if either elf departs the colony, and lapse if 500 ticks pass without proximity.

Three tick systems run the lifecycle, all every 50 ticks:

• Formation -- match eligible pairs, dissolve stale and dead-master bonds
• Effects -- award proximity XP, refresh master mood, count bond strength
• Graduation -- detect skill-10 students, sever the bond, apply social effects

A separate aesthetic drift system runs once per day to slowly pull the apprentice's aesthetic position toward the master's.

Source: crates/er-sim/src/sim/systems/apprenticeship.rs; crates/er-sim/src/sim/systems/aesthetics.rs, apprenticeship_aesthetic_drift_system.

How It Works

Formation Eligibility

Every 50 ticks the formation system snapshots all elves and looks for unbonded pairs that match all of:

Only Compose, Build, and Gather tasks count as skill exercises. A master idling does not exercise their skill, and so cannot form a bond that tick. A pair must be actively working the same craft, near each other for the match to fire.

The matcher takes the first eligible student per master (sequential pass; no scoring). One student per master per pass.

Source: crates/er-sim/src/sim/systems/apprenticeship.rs, apprenticeship_formation_system -- task_to_skill, eligibility filters at lines 137-148.

Bond Strength

bond_strength (0--255) increments by +1 every 50 ticks the pair stays within 5 tiles. It is the count of proximity ticks the bond has accumulated. It never decreases except by dissolution. Three thresholds matter at graduation:

Reaching 200 takes 200 proximity ticks = 10,000 ticks of continuous near-master work. A bond can persist longer than that without graduating if the student's skill is still climbing.

Source: crates/er-sim/src/sim/systems/apprenticeship.rs, apprenticeship_effects_system; graduation tiers at lines 322-324.

Effects (Per 50-tick Tick)

While the pair is within 5 tiles:

The XP bonus is small but constant. Over a full apprenticeship a student typically gains hundreds of bonus XP from proximity alone, accelerating their climb to skill 10.

Source: crates/er-sim/src/sim/systems/apprenticeship.rs, apprenticeship_effects_system -- proximity check at line 217, mutations at lines 224-243.

Aesthetic Drift

Once per day, every apprentice within 5 tiles of their master drifts 0.02 along each aesthetic axis (structure, tradition, emotion, social) toward the master's value. This is 2x the friend drift rate. The pull is signed -- it always moves toward the master, clamped to [0.0, 1.0].

Apprentices learn what their master values, not just what their master does. An apprentice studying under a deeply traditional master will gradually become more traditional themselves, even if they entered the bond as a radical.

This drift persists in the student's aesthetic position after graduation -- the bond ends, but the imprint remains.

Source: crates/er-sim/src/sim/systems/aesthetics.rs, apprenticeship_aesthetic_drift_system -- APPRENTICE_DRIFT_RATE = 0.02, proximity check at 5 tiles.

Graduation

When a student's skill in the bonded craft reaches 10, the next graduation pass resolves the bond:

1. Remove Apprenticeship from student and HasApprentice from master.
2. Attach a permanent TrainedBy { master_name, skill } component to the student.
3. Apply mutual relationship bonus (+15, +20, or +25 depending on bond strength).
4. Push "Graduated" mood +8 on the student for 300 ticks.
5. Emit a Graduation event (notable priority -- shows in event feed).

The TrainedBy component is permanent and visible in the elf detail panel as Trained by {master} ({skill}). It marks lineage even after the master has departed.

Source: crates/er-sim/src/sim/systems/apprenticeship.rs, apprenticeship_graduation_system -- skill 10 gate at line 279, bonus tiers at lines 322-324.

The Surpass Branch

If the graduating student's skill is strictly greater than the master's at graduation time, a StudentSurpassedMaster event fires. The master's reaction depends on their tradition axis:

A traditional master expects deference and grades the apprentice's success as a slight against the lineage. An open master treats it as the system working as intended -- the student became greater than the teacher, which is the point.

This branch fires once per (student, master) pair for the lifetime of the colony, tracked by the surpass_acknowledged set. A student who surpasses a master, leaves the colony, and returns will not re-trigger the event.

Source: crates/er-sim/src/sim/systems/apprenticeship.rs, apprenticeship_graduation_system -- surpass check at line 348, tradition threshold 0.6 at line 352.

Maintenance and Dissolution

The formation system also handles cleanup every 50 ticks:

Stale bonds dissolve quietly (no event). A master and student who drift apart -- because tasks reassign or one moves to a distant zone -- will lose the bond after about 10 game days of separation.

Source: crates/er-sim/src/sim/systems/apprenticeship.rs, apprenticeship_formation_system -- staleness at line 104; cleanup_apprenticeship_on_departure.

Interactions

Composition Style

Every composition by an active apprentice gets the InStyleOf({master_name}) composition property. It is cap-exempt (does not count toward the 2-property limit), inserted alongside the seasonal property.

A composition titled Wistful Sonata of Fellowship written by an apprentice of a master named Calenor will display the property as Style: Calenor. It marks the work as belonging to a lineage. The property is attached only while the bond is active -- post-graduation compositions do not carry it (the lineage lives in the TrainedBy component instead).

Source: crates/er-sim/src/sim/systems/compose.rs, lines 189-192; crates/er-sim/src/sim/components.rs, CompositionProperty::InStyleOf.

Mentor Relationships

The master-student bond does not show up in the relationship list while the apprenticeship is active -- it is a separate component. Only at graduation do the two elves exchange a permanent +15..+25 relationship strength bonus, which generally pushes them firmly into Friend territory and often beyond.

The surpass branch can flip this: a traditional master who feels surpassed loses 10 relationship to the student (net result: typically still positive, but smaller). An open master gains an extra +10 (deep, lasting friendship).

Lifecycle and Departure

When a master departs, their student loses the bond and takes a -8 mood penalty. The aesthetic drift the student has accumulated remains. The TrainedBy component, if already set by an earlier graduation under a different master, is preserved -- a student can only have one TrainedBy at a time, but lineage records are not retroactively erased.

Elder masters who depart through fulfilled departure leave behind students who must finish learning on their own. The master's name lives on as master_name in the (now-orphaned) lineage record.

Aesthetic Position Convergence

Pairs that maintain the bond for a full season can drift up to 0.02 x days in each axis -- enough to noticeably shift an apprentice's aesthetic identity. Two elves who started 0.4 apart in tradition can converge to within 0.2 over a long apprenticeship.

This is one of the few systems in the game that changes an elf's aesthetic position after personality maturation. Most aesthetic shifts come from environmental drift; apprenticeship is targeted, directional drift.

Tips

• Pair masters and apprentices in the same workshop. The matching system requires both elves to be actively performing the same task within 5 tiles. Co-locating composer huts, builder yards, and gathering paths gives the matcher more candidate pairs to work with.

• Aesthetic alignment is not required for formation -- only skill and proximity. A radical apprentice can bond with a traditional master, and the drift system will pull them toward the master's aesthetic over time. This can be used deliberately to shift a colony's aesthetic balance: appoint elders with the values you want to preserve, and apprentices will inherit them.

• Watch for the surpass event. If your master's tradition is high (> 0.6), a strong apprentice will eventually surpass them and trigger resentment. The master's +5 Rivalry inspiration can fuel new compositions (Manifesto, Obsessive, Virtuosic require Rivalry > 30) -- but the -10 relationship hit can also push them toward departure if they were already strained.

• Long apprenticeships are not punished. A bond at strength 200+ gives a +25 relationship bonus at graduation, vs +15 for a quick match. There is no maximum duration; bonds can run thousands of ticks. The only cost is opportunity -- a low-skill student locked into one master cannot learn from anyone else.

• InStyleOf is a lineage marker, not a quality bonus. The property does not affect mastery, originality, or emotional scores -- it is purely informational. A composition's quality still depends on the composer's own skill, inspiration, and mood. The marker matters for cultural history (which master shaped which compositions), not for revel performance.

• Don't over-cluster apprenticeships in one craft. A master can only hold one apprentice. If you have three skill-9 builders and only one skill-2 builder, two of your masters will sit unbonded. Spread skill levels across crafts to maximize the number of active mentorships.

• Bonds dissolve quietly. If a master is reassigned to a task that doesn't exercise the bonded skill, the pair will stop accumulating proximity ticks and the bond will lapse after 500 ticks of inactivity. There is no warning -- the apprentice simply loses the bond and will be re-matched (potentially to a different master) on the next formation pass.