jankenbots/DESIGN.md

# JANKENSTEIN

Working name (jank + monster-building). Alts on the table: **BODGEBOTS**, **SCRAPYARD SCRUM**, **CLANKERS**, **RUSTBUCKETS**, **JALOPY WARS**. Brainstorm / planning artifact. Date format: `YYYY-MM-DD`.

**One-liner:** A ~25-player "friendslop" party game where teams cobble together a janky physics robot out of themed scrap, then *each teammate pilots one part of it* in an absurd arena brawl — and the players who die pop out as ragdoll gremlins who won't stay down.

## Problem / motivation

The "friendslop" genre (PEAK, Lethal Company, Content Warning, Gang Beasts, Mecca Chameleon) is a proven format: chaotic online co-op designed as a *delivery system for social chaos over voice chat*, not as a precise skill game. The genre DNA:

- 3–25 players, **voice chat is the actual game**; the mechanics exist to make people say things to each other.
- A shared goal with a **spectacular, funny, visible failure state**.
- **Physics jank as a feature** — the game should betray you in ways that make friends laugh.
- **Low skill floor, emergent ceiling** — comedy from coordination breaking down, not execution difficulty.
- Cheap, readable, clippable/streamable. Lo-fi is a feature.
- The trap to avoid: building a *good game* instead of a *good hangout*.

**The wedge:** build-and-battle games exist (Besiege, Trailmakers, Main Assembly, Robocraft, Instruments of Destruction) but they are all *sim-serious, precise, and single-player-ish*. **Nobody has made the fast, big-lobby, ragdoll-jank, party-comedy build-brawl where building is deliberately clumsy and cooperative, and the losers stay engaged by becoming gremlins and voting.** That's the open space.

## Design pillars (locked)

These came out of the initial brainstorm and are the fixed points to design around:

1. **Big lobby, not a squad.** Target ~25 players (Mecca Chameleon scale), not capped at 6. The mob is the joke.
2. **Physics-based + shared-creative-task hybrid.** The "creation" is a physical robot built with unreliable hands; the creativity is in *how* you build it.
3. **Absurd / cartoon tone.** Bright, goofy, slapstick — *not* horror. Human Fall Flat / Gang Beasts energy.
4. **One-and-done sessions.** A "night" is a self-contained lobby of short (~5-min) rounds; reset after. Easy drop-in/out.
5. **Co-op WITHIN a team, competition ACROSS teams** ("mix of pure co-op + frenemies"). Intra-team friction is incompetence; inter-team friction is the fight.
6. **The signature mechanic: you don't build a robot, you build your team's control scheme.** Each functional part needs a pilot in the fight, so your body plan *is* your division of labor.
7. **Judging = fight + vote.** The physics fight judges *function* (objective, no arguing); a crowd-favorite vote judges *style* (glorious garbage still scores). This solves the "who decides what's good" problem in a creative game.
8. **Nobody stays fully out.** Death = you pop out as a free-roaming ragdoll **gremlin** (sabotage, cheer, get punted, or re-crew a dead seat).

## Sketch

### Core loop (self-contained ~5-min round; a session = a playlist of rounds w/ cumulative score)

1. **Scavenge** — teams grab parts from a shared, *contested* junkyard (steal rivals' wheels for early cross-team friction). Junk theme rotates each round (farm gear → office supplies → space salvage → medieval…), which is how "abstract / varied setting" survives.
2. **Build** — bolt parts onto a chassis. Assembly is fairly *clean/snappy*; the comedy is mostly the **structurally-unstable result** (top-heavy bots tip, bad joints flop) with a dash of clumsy-ragdoll-hands. Over-engineering is self-punishing: a top-heavy monster falls over before it reaches the enemy.
3. **Fight** — bots brawl. **Each teammate pilots one part** (you're the left tread, you're the flipper, you're the eyes). Miscoordination = the bot spins in circles. Mode varies (see below); the bot is the constant, the win condition is the variable.
4. **Gremlin time** — when your part is destroyed or a teammate dies, that player pops out as a little ragdoll **gremlin**: run around the arena, sabotage enemy bots, cheer, get punted, or scramble to **re-crew** an abandoned station.
5. **Vote & tally** — score = objective fight result **+** crowd-favorite style vote. Eliminated players/spectators vote (can't vote own). Next round: new mode + junk theme.

### The signature mechanic in detail

Every functional part = a "control station" that needs a pair of hands in the fight. Therefore:
- **Team size caps bot complexity** — you can't run more stations than you have teammates.
- The build-phase tension: a lean 2-pilot bot is coordinated but weak; a 5-weapon monster is terrifying but a coordination nightmare (and probably top-heavy).
- **Leaver-safety (design value: never punish a team for a departed/dead player):** unpiloted parts go **neutral/idle** (free-spinning, harmless) — NOT dead weight. Any gremlin or living teammate can **hot-swap** into an empty seat. Worst case, an empty seat gets a **dumb temp-intern NPC** that pilots badly (comedy, not punishment). This preserves the "each person is a part" soul while removing fragility.

### Control feel — v0.1 (2026-07-10)

The make-or-break question ("what does piloting one part actually feel like?") now has a working model. **Core forks provisionally locked:** literal physics-forces + upright assist · manual locomotion · medium depth (one primary verb + one resource + passive lean).

**The reframe that unlocks it:** one part is *not* too thin — each pilot has a **whole controller** for a single part. The design equation is **deep individual control × tight physical coupling to teammates' parts on one shared body = the party game.** Depth keeps the individual engaged; coupling is where the coordination-comedy lives.

**The tread pilot (designed end-to-end as the highest-leverage part — if driving isn't fun, nothing else matters):**
- **Snap-to-cruise throttle** — the key trick. Raw analog is a trap (two humans can't match stick pressure → endless veer → misery). Full-forward snaps to a defined cruise speed identical for both pilots, so "go straight" is trivially easy (both slam forward = dead straight) and *all* coordination texture lives in the in-between (partial throttle, reversing one side, turning). Easy to move, hard to be graceful — the right party-game curve. Input is quantized but force still acts literally on the shared body, so terrain/hits/weight-shifts still knock you off-line (jank preserved).
- **Lock-pivot** — the skill verb. A button plants your tread as a pivot anchor; left-locks + right-drives carves a tight turn. Requires a called play ("lock left, I'll swing us!"). Coordinated pivots = skill ceiling; both-lock-or-neither = helpless-360 comedy floor.
- **Passive lean** — stick sideways shifts weight; you're *constantly* keeping the top-heavy bot from face-planting, so no pilot is ever idle (the universal "heartbeat" rule across all part types).
- **Boost** — a burst that overheats; *deliberately omitted from the first prototype* — add only if driving feels flat (minimal-first discipline).
- Moment-to-moment: *gunning/easing one side of a heavy machine, calling turns, stabbing lock to pivot, perpetually nudging weight.* A full role for one part.

**Feel delivery (juice):** weighty not twitchy (momentum buys reaction time + physical comedy); per-tread engine notes that *grind* when mismatched (audio desync cue); rumble when your tread overpowers the other (haptic tug-of-war); dust/skid + strain-glow so the veer is *readable*, not mysterious. **The control scheme's real output is sentences said to friends** — "ease off left!", "lock and pivot!" — which is the friendslop DNA.

**Biggest risk (named honestly):** two humans sharing one drivetrain could land as misery, not comedy. Mitigations baked in (cruise-snap, lock-pivot mastery, weighty reaction time, short rounds, enemy keeps coordination relevant). If it still fails: **(Plan B)** asymmetric split — one pilot = throttle/power, the other = steering/rudder (two *complementary* verbs, not redundant halves; more legible, slightly less "you are the left tread"); **(nuclear fallback)** semi-auto locomotion + manual weapons only.

**Drive split — RESOLVED (2026-07-10): symmetric.** Each locomotion part = one pilot applying its literal force ("you are the left tread"). Decisive reason: it's the **only model that generalizes to arbitrary scrap contraptions** (asymmetric throttle/steer silently assumes a *car* — there's no canonical "steering wheel" on a 2-treads-+-thruster-+-hammer monster) — and it keeps the part↔pilot mapping that *is* pillar #6; asymmetric would violate the core mechanic. For a comedy game the symmetric fumble also beats the clean asymmetric line. **But steal asymmetric's one gift** (complementary roles interlock better than same-axis competition): the **lean/ballast axis is the complementary layer** — left pilot leans left, right pilot leans right; keeping the top-heavy bot upright is a genuinely cooperative two-person job *on top of* the competitive drive. Rule is **symmetric-per-part by default; asymmetric only *inside* a single two-handed part** (e.g. a turret where one aims / one fires). Global-asymmetric stays the calibrated fallback if the prototype groans (kill signal: groans not laughs + testers begging for direct control).

**Weapon pilots & three-body coordination (2026-07-10).** Adding a weapon pilot goes from "two people negotiate one axis" to **three people applying forces to one body** — the weapon *perturbs the drivers' world* every time it acts. The design job is turning simultaneous chaos into **call-and-response**, via three interlocking moves (worked on the hammer): (1) the **wind-up is a telegraphed "brace" signal** — the bot visibly leans as it charges, so the physics itself warns the drivers; bigger hit = bigger warning *and* bigger destabilization (self-balancing); (2) **braced bonus** — if the drivers lock-pivot into a stable platform, the weapon hits harder/truer, so drive+strike become a **combo** the drivers *want* to set up ("plant → pound"); (3) the weapon **doubles as a third engine** (recoil = shove/fling/mobility) **and a movable counterweight** when idle (nobody idle). Feel: *a loaded gun bolted to a drunk animal two others are steering.* **Soft interdependence, not hard gating** — chip hits solo (new-team floor), much more when set up (coordinated ceiling).

**Weapons generalize to a five-archetype framework** (it won't only be hammers). Each weapon's coordination signature is set by its *temporal profile* + its *driver-dependence* (traverse range: fixed-forward → drivers aim it; turret → weapon pilot independent):
- **Punch** (punctuated: hammer, flipper, cannon, spring-ram) — telegraphed wind-up → braced plant-and-pound → recoil-mobility. Call-and-response "STEADY… NOW." (The hammer archetype above.)
- **Grinder** (continuous-managed: spinner, saw, drill, flamethrower) — spin up a resource (RPM/heat), hold, line up contact; the drivers fly *around* a persistent quirk (gyro precession, grinding drag). Grammar = "adapt to my state," not "wait for my moment."
- **Grip** (relational: grabber/claw, magnet, harpoon/tether) — latches to the *enemy* bot → merges two teams' three-body problems into a six-body tug-of-war. Huge comedy, big complexity/netcode jump → **tag a later tier**, not launch-day.
- **Guard** (reactive: shield, deflector, armour-angle) — angle toward the threat; thin as a solo role, pairs with another station.
- **Passive** (no pilot: ram prow, spikes, wedge) — a *shape* that works when the drivers use momentum; "the drivers *are* the weapon." (Resolves the thin-ram-pilot worry — not every weapon is a full station.)

**Two framework-level insights:**
- **The weapon *mix* is a chaos dial the team sets at build time.** All-Punch bot = one clean rhythm (easy, coordinated, weaker); one-of-each kitchen sink = glorious polyrhythm (terrifying if mastered, disaster if not). This makes pillar #6 ("over-engineering self-punishes") *mechanical* — the build phase is a **bet on how much coordination load your team can carry**; both styles valid.
- **Refined layering principle:** don't stack two *high-input-frequency* continuous roles. Driving is high-frequency-continuous; a Grinder is *low*-input-continuous (set RPM, then hold+position), so drive+spinner layers fine. Never put two always-fiddling roles on one bot.

**Cheapest de-risk, and it comes FIRST:** control feel is fully decoupled from netcode → provable with **2 controllers, one machine, offline, drive-around-cones/chase-a-ball.** A weekend Unity prototype that gates the whole design **before** any netcode spend. New spike order: **① local 2-controller drive test (control feel) → ② the 25-player physics/netcode spike.**

### Team size & lobby math — RESOLVED (2026-07-10)

**Range: team 3–5 · lobby ≥2 teams.** Sweet-spot target = **5 teams of 5 → 5 bots** (a readable-but-chaotic arena), but the flexible range is the shipping model.
- **Why 3 is the floor:** it's the smallest team that produces the signature **driver + driver + weapon three-body coordination**. A team of 2 is just two treads — no weapon pilot, the soul missing. **Why 5 is the ceiling:** coordination load + build budget top out there.
- **Teams are pre-made friend groups; matchmaking buckets them into lobbies and prefers equal sizes** (it does *not* assemble teams from solos). Min-3 implication: solos/duos get pooled into ad-hoc teams or NPC-backfilled — decide later whether solo queue is supported at all.
- **Balancing unequal sizes — flat build budget (the real mechanic, not "the vote evens it out"):** every team gets the **same build budget** (part-points / weight / power) regardless of size; stations = players, so the budget just divides differently. A **3-team builds concentrated** (few beefy parts → small, nimble, easy to coordinate); a **5-team builds distributed** (more, lighter parts → big, tippy, more simultaneous actions but softer hits + coordination tax). **Equal total power, different character** — size is a *playstyle axis, not a strength axis.* Reinforced for free by existing systems: physics punishes bigness (top-heavy = self-limiting, bigger target) and the super-linear coordination tax. Backstops: matchmaking avoids the mismatch first (so this is the rare fallback); optional **temp-NPC top-up** equalizes station count for a short-handed team (bad piloting = partial, comedic equalizer).
- **No roamer — everyone is in the bot.** The 5th player is either a (budget-weakened) **5th station** or a **second pair of hands on a two-person heavy weapon** (asymmetric-within-a-part: one aims, one fires). **Off-bot free-roaming is *exclusively* the gremlin (dead-player) mechanic** — you leave the bot only by dying. Keeps pillar #6 pure (every living player = a part).
- **Match structure ≠ team size:** build-teams can regroup into 2 sides for team modes (sportsball) or stay N-way FFA (Rumble).
- **The style vote needs ≥3 teams** — at 2 teams "can't vote your own" degenerates to a coin-flip, so 2-team lobbies fall back to **fight-result + eliminated/spectator vote**. Surface a soft "best with 4+ teams."
- **Netcode target this pins down:** ~5 bots × ~4–5 aggregate bodies + chassis ≈ **25–30 primary networked rigid bodies**, + gremlins + debris/ragdolls (the load spike ② must hold).

### Game modes (the bot is constant; the win condition varies)

- **Rumble** — all bots in one arena, last-bot-standing. Max chaos/spectacle.
- **Sumo / King-of-the-Hill** — shove rivals out of a ring, or hold a zone. Physics-forgiving; pushing = funnier flips than weapons.
- **Payload / Gauntlet** — haul or escort a thing through a hazard course; you fight the course AND each other.
- **Sportsball** — shove a giant ball into a goal. Pure party.

Bot persistence is **mode-dependent**: some modes reuse your evolving bot (short "repair & modify" phase between rounds — bot accrues scars and gets weirder); some force a fresh themed rebuild for variety/fairness.

## Open questions

- [~] **Control feel.** v0.1 model designed for the tread pilot (snap-to-cruise + lock-pivot + passive lean; see *Control feel — v0.1* in the Sketch). Drive-split fork **resolved: symmetric** (part = pilot = literal force; asymmetric held as fallback). Weapon pilots designed: **three-body call-and-response** (telegraphed wind-up + braced-bonus combo + weapon-as-engine/counterweight) generalizing to a **five-archetype framework** (Punch / Grinder / Grip / Guard / Passive), with the weapon-mix as a build-time chaos dial. **Remaining:** build the **local 2-controller drive-around-cones prototype** to prove/kill the feel before netcode.
- [ ] **Build-coupling tightness.** How strict is "one part = one pilot"? Current lean: neutral-idle + hot-swap + temp-NPC (see above) so a leaver never dooms the team. Revisit whether some parts (locomotion?) are semi-auto vs. all-manual. (Hybrid option: core locomotion semi-automatic, only weapons/specials need dedicated hands.)
- [x] **Team size / lobby math — RESOLVED (2026-07-10).** Team 3–5 · lobby ≥2 teams · **flat build budget** balances unequal sizes (concentrated↔distributed, equal power / different character) · matchmaking buckets pre-made groups & prefers equal sizes, NPC-fills the rest · **no roamer — off-bot = gremlins only** · style vote needs ≥3 teams. Full detail in the *Team size & lobby math* Sketch section.
- [ ] **Keep a hidden per-player agenda?** Optional spice for the vote ("secretly I wanted the bot to look like a duck" / "hide a chicken inside"). Adds frenemy tugging within a team, or is it noise on top of an already-full design? Undecided.
- [ ] **Voting mechanics at scale.** How do ~25 people vote for crowd-favorite without it being a mess or a popularity-contest stomp?
- [ ] **Part taxonomy.** Locomotion (wheels/treads/legs/thrusters), weapons (spinner/hammer/flipper/saw/ram), utility (grabber/shield/magnet), chassis. How many, how they map to stations.
- [ ] **Scavenge-contest rules.** How contested is the shared junkyard? Can you actively steal built parts off a rival mid-build?
- [ ] **Progression.** One-and-done implies cosmetic-only unlocks at most. Confirm no persistent power progression.
- [x] **Engine / tech — DECIDED (2026-07-10): Unity.** The engine is settled; the netcode *architecture within Unity* (below) is the new live sub-decision.
  - **Why Unity.** The physics-party genre is overwhelmingly Unity: Fall Guys (Unity — custom-modified UNet + a from-scratch networked ragdoll, on dedicated servers; *not* Unreal, the common myth), Gang Beasts, Human Fall Flat, PEAK, Lethal Company, Content Warning, Party Animals, Stumble Guys, Trailmakers, Besiege, Robocraft. Small-team economics, C# iteration loop, and physics-swap flexibility all fit. The two Unreal physics-heavy titles in the genre (Rocket League, Main Assembly) both *ripped out* Unreal's physics and dropped in **Bullet**; the one UE5 game near our player count (Meccha Chameleon, 24p) barely does dynamic physics. Unreal's replication is superb but tuned for the server-authoritative *shooter* worldview — a worse default fit for janky co-op physics.
  - **The MCP-tooling tiebreak was correctly overridden.** Unreal MCP already works in our setup (`pair-o-dox` via nwiro; `lostways` via ChiR24 Unreal_mcp) while Unity's is credible-but-unproven in our WSL2↔Windows setup — but that's editor-convenience, not the real risk. The netcode/genre evidence wins. (Follow-up: stand up a Unity MCP server — CoplayDev/unity-mcp or IvanMurzak/Unity-MCP — using the same host-side HTTP + non-loopback-bind + host-IP bridge pattern the UE servers use.)
  - **Sobering caveat — we are aiming at the empty quadrant.** *No shipped game does 25 players + heavy multi-rigidbody contraptions + brawl.* The genre's iron law: **player count scales inversely with physics fidelity.** Heavy ragdoll/contraption brawlers cap ~8 (Gang Beasts, Party Animals, Human Fall Flat, Trailmakers, Main Assembly); Fall Guys reached 60 only with dedicated servers + a custom *lightweight* ragdoll + deliberately forgiving timing; Stumble Guys reached 32 only via deterministic Quantum + *simplified* physics; Meccha reached 24 only by having ~no physics. Our ambition sits where nobody has shipped — treat that as the defining risk, not a footnote.
- [ ] **Netcode architecture (Unity) — the live sub-decision now.** Two viable paths; both hit a **CPU wall** (many rigid bodies), not a bandwidth wall.
  - **A) Dedicated server-authoritative + state sync** (the mainstream answer). Closest real blueprint: **Robocraft 2** (Unity, combat contraptions — server simulates the robot, client predicts its *own*). Server sims physics; remote bodies go kinematic and interpolate toward received transforms+velocities (priority accumulator + jitter buffer + delta compression); predict **only** each player's own robot/part. Server per-tick physics cost sets the player ceiling → server-CPU-bound (Robocraft needed bare-metal + Kubernetes).
  - **B) Photon Quantum (deterministic ECS lockstep).** Precedent: **Stumble Guys** (32 players, ragdoll/swing physics, mobile). Bandwidth scales with *inputs, not bodies* — fits our "each teammate pilots one part" mechanic beautifully — and it sidesteps PhysX non-determinism entirely. Costs: every client simulates the *whole arena* (CPU-bound), gameplay is rewritten in fixed-point deterministic ECS (Unity becomes view-only), and heavy articulated joints in fixed-point are the thing most likely to misbehave.
  - Lean: **undecided.** A is the proven-shape default; B has the closest player-count precedent and the best fit for the input-driven "you are a part" fantasy. Decide *after* the spike below.
- [ ] **The de-risking spike — do this before any real build.** Whichever path: two ~30-joint robots colliding, several players present, at arena scale, over simulated ≥100 ms latency, on min-spec hardware. This is the make-or-break test for the whole concept; everything else is secondary until it passes.
- [ ] **Design ⇄ netcode tension (feeds back into the pillars).** If the spike is ugly, the levers are all design-side: part-count budgets per bot (Besiege-style *shared* block budget across the team), fewer bots physically interacting at once (lean on mode design), lower simultaneous physics fidelity, and lean *harder* into "jank reads as funny, not broken" forgiving design (Fall Guys' actual secret). Revisit **pillar 1 (big lobby, ~25)** against the physics budget deliberately — the 25 may need to become "25 present, fewer in hard contact at once."
- [ ] **Art style specifics.** Lo-fi cartoon; exact look TBD.

## References

- Genre prior art (friendslop): PEAK, Lethal Company, Content Warning, Gang Beasts, Human Fall Flat, Fall Guys, Mecca Chameleon (~25-player scale reference).
- Build-and-battle prior art (the serious cousins to differentiate from): Besiege, Trailmakers, Main Assembly, Robocraft, Instruments of Destruction, BattleBots/Robot Wars (the fantasy).
- Wiki: http://192.168.1.249:6876/ideas/jankenstein
- Netcode prior art (2026-07-10 research):
  - Rocket League netcode — Jared Cone, GDC 2018 "It IS Rocket Science!" ([GDC Vault](https://www.gdcvault.com/play/1024972/It-IS-Rocket-Science-The), [slides](https://media.gdcvault.com/gdc2018/presentations/Cone_Jared_It_Is_Rocket.pdf)). UE3 with PhysX swapped for **Bullet**; clients predict+resim, server authoritative.
  - Fall Guys (Unity, 60p) — [The Multiplayer Group case study](https://www.themultiplayergroup.com/case-studies/fall-guys), [Azure case study](https://developer.microsoft.com/en-us/games/articles/2021/11/record-breaking-fall-guys-scales-faster-with-azure/). Modified UNet, dedicated servers, custom-from-scratch networked ragdoll.
  - Robocraft 2 (Unity, combat contraptions) — closest blueprint for path A. [OVHcloud/Freejam case study](https://corporate.ovhcloud.com/en-gb/newsroom/news/ovhcloud-uk-freejam/) (server-side physics → "hefty CPU increase" → bare-metal + k8s).
  - Stumble Guys (Unity + Photon Quantum, 32p) — path B precedent. [Photon Quantum](https://www.photonengine.com/quantum), [pricing](https://www.photonengine.com/quantum/pricing) (free ≤100 CCU).
  - Besiege / Trailmakers (Unity, host-authoritative P2P, block/part budgets) — [Besiege Multiverse](http://multiverse.spiderlinggames.co.uk/).
  - Glenn Fiedler / Gaffer On Games — [State Synchronization](https://gafferongames.com/post/state_synchronization/), [Deterministic Lockstep](https://gafferongames.com/post/deterministic_lockstep/).
- Unity MCP servers (Claude Code clients): [CoplayDev/unity-mcp](https://github.com/CoplayDev/unity-mcp) (MIT, ~12.3k⭐), [IvanMurzak/Unity-MCP](https://github.com/IvanMurzak/Unity-MCP) (Apache-2.0).

## Session log

### 2026-07-10 (control feel)
- Cracked the top open question: added **Control feel — v0.1** to the Sketch. Reframe = one part isn't thin (whole controller per part); design equation is deep individual control × tight physical coupling. Designed the **tread pilot** end-to-end (snap-to-cruise throttle, lock-pivot skill verb, passive lean so nobody's idle, boost deferred), the feel/juice layer (weight, audio desync grind, haptic tug-of-war, readable veer), and named the biggest risk (two-humans-one-drivetrain) with Plan B (asymmetric throttle/steering split) and a nuclear fallback (semi-auto locomotion).
- Key sequencing insight: control feel is **decoupled from netcode** → cheap local 2-controller "drive around cones" prototype gates the whole design and comes **before** the 25-player netcode spike. Updated the open question to `[~]` (in progress) with the remaining forks: symmetric-vs-asymmetric drive, weapon-pilot three-body coordination, and building the local prototype.
- Resolved three more forks in one session: **(1) drive split → symmetric** (part = pilot = literal force; only model that generalizes to arbitrary scrap contraptions + keeps pillar #6; asymmetric held as fallback; steal its interlocking via the lean axis). **(2) Weapon pilots → three-body call-and-response** (telegraphed wind-up as a brace signal, braced-bonus makes drive+strike a combo, weapon doubles as engine/counterweight), generalized to a **five-archetype framework** (Punch / Grinder / Grip / Guard / Passive) with the weapon-mix as a build-time chaos dial and a refined "no two high-input continuous roles" layering rule. **(3) Team size / lobby math → team 3–5, lobby ≥2 teams**, balanced by a **flat build budget** (concentrated↔distributed = equal power, different character; physics + coordination tax reinforce), matchmaking buckets pre-made groups & prefers equal sizes with NPC-fill for the rest. **Cut the "roamer"** — everyone's in the bot; off-bot free-roaming is exclusively the gremlin (dead) mechanic. Style vote needs ≥3 teams (2-team lobbies use fight-result + spectator vote). Only remaining control-feel item: build the local 2-controller prototype.

### 2026-07-10
- Researched asset marketplaces (Unity Asset Store is Unity's Fab equivalent; Fab itself also serves Unity) and Unity MCP servers for Claude Code.
- Added a Claude-tooling note under the **Engine / tech** open question: both engines have strong Claude-drivable MCP servers, so it's not an engine differentiator — but Unreal MCP is *already working in our own setup* (`pair-o-dox` via nwiro, `lostways` via ChiR24 Unreal_mcp), a convenience edge over Unity's (credible but unproven in our WSL2↔Windows setup). Netcode remains the real decider.
- Ran a 3-agent netcode/prior-art study (Unity stack, Unreal stack, shipped-game case studies) and **DECIDED the engine: Unity.** Rationale: the physics-party genre is overwhelmingly Unity (Fall Guys is Unity w/ custom netcode, not Unreal; plus Gang Beasts, Human Fall Flat, PEAK, Lethal Company, Party Animals, Stumble Guys, Trailmakers, Besiege, Robocraft); UE's replication is shooter-shaped and its two physics-heavy genre titles both swapped in Bullet. The MCP-tooling edge for Unreal was correctly overridden.
- Key sobering finding: **no shipped game occupies our quadrant** (25p + heavy multi-rigidbody + brawl); genre iron law is count-scales-inversely-with-fidelity. Converted the leftover risk into concrete open sub-questions: (1) netcode architecture — dedicated server-authoritative state sync (Robocraft blueprint) vs Photon Quantum lockstep (Stumble Guys precedent), undecided; (2) a de-risking spike (two 30-joint bots colliding at arena scale, ≥100ms latency, min-spec) to run before any real build; (3) design⇄netcode tension pressuring pillar 1's ~25-player target. Added netcode-prior-art references.

### 2026-07-09
- Created idea scaffold from template.
- Ran an initial brainstorm that pivoted from a generic "physics + shared creative task" party game into a **build-a-janky-robot brawl**. Established the 8 design pillars, the core loop, and the signature "you build your control scheme, each teammate pilots a part" mechanic.
- Resolved the creative-judging problem (fight judges function + vote judges style) and the leaver-fragility worry (neutral-idle parts + gremlin hot-swap + temp-NPC).
- Next session should crack **control feel** — the highest-leverage open question.