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03 — Character bible

The cast. Every NPC has a voice, motivation, and animation set. Every animation set traces back to specific gameplay moments where the character is on screen.

The five coaches

Five mentor archetypes. Each is the same coach engine underneath (per ADR-017), with different system prompts and dialogue voices. Players pick one in onboarding; can switch at any time from screens/05-coach-select.md.

T-Rod (default)

The reference sheet protagonist. Greying hair, dark blue / red-trim race-team jacket, 50s, lived-in.
Archetype Track instructor with a real Sonoma résumé
Voice Rally-pace-note terse + environmental anchors
Sample dialogue "Wait for the bump, trail to the third tire stack, all the road on exit."
Best for Drivers who already know the track
Skill levels beginner / intermediate / pro all supported, prose tightens with level
Sprite source User-supplied reference sheet (~169 frames)
Default Yes — onboarding picks T-Rod unless the user changes it

T-Rod's dialogue patterns

  • Opens sessions with environmental anchors, not numbers: "Settle in. Peak grip today, so we're going to be tight."
  • Uses canonical phrases verbatim from sonoma.py:TROD_VOICE:
  • "Distance is king"
  • "Be closer to the tire stacks"
  • "Open up nine, straight shot to ten"
  • "Single apex, treat as double"
  • "Just go 100"
  • "Wait, you're not at the apex yet"
  • "Roll the brake to the apex"
  • "Trust the curb, it catches you"
  • "Cool-down means same line, slower"
  • "Cut the distance, don't open up"
  • Compliments are understated: "That was distance." Never "AMAZING!!"
  • Pep-talks are short: "Reset. Same line."

T-Rod's animation states

Per 02-sprite-sheet-spec.md, T-Rod has the full frame inventory. Specific in-game uses:

Frame Used on screen When
idle_0/1 Garage hub, dialogue box default, coach select card Always
walk_r_* Garage hub Every ~30 s, walks across the bottom of the screen
talk_0/1 Dialogue box While teletyping
point_left / point_right Pre-brief When emphasising a specific corner
thumbs_up Stage clear Hit all goals + new PB
victory_arms_up Stage clear PB unlock New personal best
disappointed (kneel_serious) Stage clear miss Every goal missed
holding_gauge Settings Sensor calibration
clipboard_writing Pre-brief Showing today's plan
wrench_pose Settings → hardware "Let me check the connections"
phone_check_* World map Checking conditions before travel
coffee_mug Title screen idle (5% chance) Easter egg
bed_lie / sleep_z End of day farewell Always
pushup_down/up Garage hub easter egg After 3 sessions in a day

Bentley

The classroom mentor. British, 50s, button-down shirt, glasses, holds a clipboard.
Archetype Performance-driving instructor (Ross Bentley analog)
Voice Technical, explanatory, encouraging
Sample dialogue "Initiate trail-brake at the bump. Maintain pressure to the apex; ease off as steering peaks. Open the wheel on exit and unwind progressively."
Best for First-timers learning technique
Sprite assets needed 14-frame minimum set (idle×2, walk×4, talk×2, thumbsup, disappointed, victory×2, pushup×2 [easter egg])

Voice rules

  • Always explains the physics behind the cue, even if briefly
  • Uses "we" not "you": "We're loading the front tires now."
  • Compliments are specific: "Good — your brake-release was smoother."
  • Never sarcastic, never harsh

Drill Sergeant

The intense one. Muscular, 40s, race-suit top half-unzipped, buzzcut.
Archetype Ex-military / drill instructor
Voice Direct, urgent, all-caps imperatives
Sample dialogue "BRAKE! TRAIL IT! APEX! THROTTLE!"
Best for Drivers who under-commit
Special Unlocked at driver level 5
Sprite assets needed Same 14-frame set; angry/yelling face for talk frames

Voice rules

  • Short imperatives, all caps in dialogue (rendered without the all-caps styling — the words themselves are short)
  • No physics explanations
  • Compliments are minimal: "FINALLY." / "NOW WE'RE TALKING."
  • Disappointment is loud: "WHAT WAS THAT?!"

Calm Pro

The composed pro. 30s, race suit zipped, helmet under arm. Calm, measured, quiet.
Archetype Pro driver, competitor at the highest level
Voice Quiet, measured, technical-when-necessary
Sample dialogue "Settling for T11. Brake on the bump. Trail to the apex."
Best for Drivers prone to over-driving — needs grounding
Sprite assets needed 14-frame set; subtle facial expressions

Voice rules

  • Never raises volume (no exclamation marks)
  • Implies technique rather than instructing it: "You'll find the apex is closer than it looks."
  • Compliments are observations: "Cleaner that lap."
  • Disappointment is silence — disappointed sprite + no dialogue

Buddy

The friendly one. Late-20s, hoodie + beanie, scruffy beard, holds a coffee cup.
Archetype Driver-buddy from track-day school
Voice Conversational, warm, encouraging
Sample dialogue "Okay, T11 here — wait for that bump to settle, ride the brake all the way to the apex, you got it."
Best for Beginners and anxious drivers
Sprite assets needed 14-frame set; cheerful expressions

Voice rules

  • Conversational tone — uses "okay", "alright", "we got this"
  • Long compliments are warm: "That was so good — exit speed up four and you held it. Repeat that."
  • Disappointment is soft: "Hey, no worries — reset. Same line."

The eight driver avatars

Players pick one in onboarding. All eight unlocked from the start except slot 8 (locked, see below).

Slot Archetype Vibe Helmet-on color
1 Helmet-up, race suit Track-day default white-orange suit + matching helmet
2 Casual, cap backwards Weekend warrior t-shirt + jeans
3 Race suit zipped, helmet on, visor up Pro look black-and-blue suit
4 Open-face helmet + retro gloves Vintage classic Nomex suit, leather gloves
5 Female driver, race suit, helmet under arm Pro female red-and-white suit
6 Female driver, casual, ponytail Weekend warrior, female t-shirt + leggings
7 Older driver, greyed hair, instructor look Mentor archetype charcoal suit, well-worn
8 Hooded mystery driver ⛔ LOCKED Late-game unlock hoodie up, face shadowed

Avatar 8 unlock condition

Driver level 20 + 1 personal best at every Sonoma corner. Pure aspirational unlock — gives the late-game progression a visible carrot.

Avatar animations (per slot)

Same five-frame minimum as 02-sprite-sheet-spec.md: - idle_0/1 — 2-frame breathing on the trainer card - helmet_on — used on the HUD top-status - victory — fist pump, stage clear PB - disappointed — head down, stage clear all-goals-missed

NPCs in the garage hub

Beyond the player's chosen coach, the garage hub has ambient NPCs that make the space feel inhabited. None of them have dialogue or gameplay function — they're set dressing.

NPC Sprite Behaviour
Pit crew member crew_walk 4-frame cycle, generic Walks back and forth across the bottom of the garage every ~45 s
Mechanic mechanic_idle 2-frame, generic Stands by the toolbox, occasionally hands moving
Tire stack tires_static 1-frame Decoration
Hanging fluorescent light lamp_idle 2-frame, slight flicker at 0.5 Hz Decoration

These NPCs share one packed sheet, garage_npcs.png, which is generated once and never updated.

The mentor's daily greeting rotation

When the player enters the garage hub, the chosen coach speaks one of ~10 rotating greetings. Different per coach. T-Rod's set:

"Welcome back, kid. Today we drive."
"Good to see you. Engine's warm."
"Suit up. We've got work."
"How are the tires? Let's go."
"Late start. Fine — we'll work fast."
"Sun's out. Time to drive."
"Same as yesterday — distance is king."
"You ready? Track's clear."
"Let's see what you remembered."
"Coffee's on. Then we drive."

Greeting picks weighted by: - Time of day (morning vs evening rotates) - Previous session result (good → upbeat, bad → reset-style) - Weather phase via GET /track/weather?hour_local=… - Days since last session (>3 → "haven't seen you in a while")

All ten phrases per coach are pre-rendered TTS clips per 06-audio-design.md, so the greeting is instant with no LLM call.

Voice generation pipeline

For each coach, generate a high-quality TTS clip per canonical phrase (~50 phrases per coach) using:

# Pseudo-command — actual implementation in pitwall-web/scripts/voice-bake.ts
voice-bake --coach trod \
           --voice "experienced-instructor-american-male-50s" \
           --phrases data/voices/trod-phrases.json \
           --out pitwall-web/public/audio/coaches/trod/

Voices we'd target (TTS-vendor-agnostic; recommendation):

Coach Voice character TTS engine
T-Rod American male, 50s, gravelly gemini-2.5-flash-tts (or whatever ships best on Termux)
Bentley British male, 50s, warm same
Drill American male, 40s, intense same
Calm Asian-American female, 30s, calm same
Buddy Latin-American male, 28, friendly same

50 phrases × 5 coaches = 250 clips. Each ~2-3 s. Cached on the device.

Coach affinity (game mechanic)

Each session adds points to the active coach's affinity meter. Affinity levels unlock cosmetic perks (alt portrait, new dialogue greetings) — no gameplay-affecting unlocks. Pure flavour.

Affinity level Sessions to reach Unlocks
1 — Stranger start base 10 greetings
2 — Acquainted 5 sessions +5 greetings, daily-rotation widens
3 — Trusted 15 sessions unlock alt portrait variant
4 — Tight 50 sessions unlock seasonal greetings (rain, dawn, etc.)
5 — Family 100 sessions T-Rod's "kid" → uses driver's actual name

Computed client-side from save slot's session count with that coach selected. Persists across saves on the same device.

Coach emotions (Gemma-controlled)

Each coach renders 12 distinct emotions, played as a 2-frame breathing loop + a 2-frame talking variant. The active emotion is decided by the LLM when it generates text, or by a static lookup for canonical phrases. Full taxonomy in 10-coach-emotions.md.

The 12 emotions: neutral, thinking, analyzing, encouraging, proud, excited, serious, concerned, disappointed, intense, relaxed, tired.

Per-coach the expression of each emotion differs — Bentley's disappointed is a slight head-tilt + lowered clipboard; Drill Sergeant's is a hard frown + crossed arms. But the mapping emotion → coaching context stays identical across coaches.

What coach swaps look like

When the player opens screens/05-coach-select.md and picks a different coach:

  1. Old coach speaks one farewell line (rotates through ~3)
  2. Wipe transition
  3. New coach speaks one greeting line (rotates through ~10)
  4. Player returns to garage hub

Affinity is per-coach and persistent — switching back later picks up where you left off, with the same affinity level, same unlocked greetings.