The vocabulary of Formula None. Code, tests, issues and ADRs use these words with these meanings; when a word here and a word in the code disagree, fix the code. Terms come from the PRD (issue 1).
One racer's vehicle, driven by a human or a bot. All karts are identical at v1; the livery and the nickname floating over it tell one from another.
The driver inside the sim for a kart no human drives: the slots humans leave empty at Start, a human's kart once they disconnect or go silent, a finished kart until the race ends, and every kart through the outro. A bot reads only what any observer of the race can, the track and the karts' transforms and standings, and answers with the same input struct a human's controller produces. Bots start on the grid behind the humans. How hard they drive is the room's bot level.
How hard a race's bots drive: Basic, Pro or Ace, one of the picks on the Title Scene, fixed for the room as the course is and shown on the Room Scene. Basic drives as the bots did before there was a pick. The level varies a bot's corner speed, its rubber band's lower bound, its item use delay, its rocket start chance, whether it calls itself in for the pit lane sooner than the cliff, which every level stops by, when it drops its drifts, on worn tyres or to save them for the flag, and whether it presses for a trick, nothing else; it changes how the bots drive, not how many there are. A replay carries it.
How long a race runs, one of the picks: 3 or 5, fixed for the room (ADR 0084).
The own kart's last lap of the race's laps, from its first tick to the kart's finish. Through it the course lifts for that kart alone: the gantry reads FINAL LAP, fireworks go up over the course's landmark, the crowd comes up all round the lap and the race music plays faster and louder (ADR 0100).
The creator's choices of how a race runs, made on the Title Scene under the flags and fixed for the room: the bot level, Tyres, the laps and Weather. They travel as one value, from the Title Scene to the sim, on the wire, in the room and in a replay (ADR 0091). A field missing from a kept room or a replay reads as the race was before there was that pick. The course is picked beside them but is not one of them: it is also the room's route. Avoid: race settings, options.
The lane beside a course's start straight, from entry line to exit line, where a kart goes to get new tyres. Safe ground: no item touches a kart in it (ADR 0081). Not every course has one.
What holds a kart to the pit lane's speed limit from entry line to exit line, by itself (ADR 0081). Not a control.
A slot's own place in the pit lane, where its pit crew waits and its kart stops. Avoid: box, which is the item box; BOX is only the radio call on the Instrument panel.
The seven figures at a pit box who change a kart's tyres: a jack at each end, a gunner at every wheel and the lollipop, the holder of the sign that spins from STOP to GO on green. Each wears the driver's head with a face of their own under a headset. Presentation only: how long they take is the stop's roll. The View draws them, with the pit box's light, from the kart readout, and only near the camera.
A kart's time stationary in its pit box, rolled from the race seed, the slot and the kart's stop count; it ends on green with tyre life back at 100% (ADR 0082).
Where a race is: Countdown, Racing, Outro or Finished. Sim state, stepped like every other rule, so a solo race in the browser and a room on the server run the same lifecycle. Countdown holds the karts on the grid for the 5 s of the start lights, during which the throttle sets up the rocket start. Racing runs the laps and ends when every human's kart has finished or is driven by a bot, or 60 s after the first human finished driving their own kart; the unfinished are placed by progress at that point and the standings become the results. Outro holds the Race View for 3 s with a bot driving every kart and the FINISH banner up for every player. Finished leaves the race as it is. A room's Countdown and Racing states follow the race's phase, its Racing state covering the Outro too, and its Results state its Finished (ADR 0032).
The five lamps the Instrument panel lights one per second through the countdown and puts out at Go, when GO shows for a second (ADR 0040).
A kart past the line on its last lap. Its finish time and place are final, it counts no more laps, and a bot drives it until the race ends, taking and firing no items; its human's inputs are ignored. A finished player sees the FINISH banner with their place and the finishers so far in place of the lap readout.
What the throttle hold ending at Go earns, read from the hold's length; a release before Go resets it, and the throttle counts as held above half. Its outcomes are the start boost and the stall. A hold longer than 2.0 s, begun before the fourth light came on, stalls the kart: 2.0 s dead to every control, as in a spin-out. A hold of 1.5 to 2.0 s, begun in the first half of the fourth light, earns the full start boost, 1.5 s at +40 percent, the boost item's values. A hold of 1.0 to 1.5 s, begun in the second half of the fourth light, earns the weak start boost, 0.6 s at +30 percent, the orange mini-turbo's values. A shorter hold, begun at the fifth light or later, starts clean. Bots roll the full boost or a clean start once per race from the seed and never stall; a kart handed to a bot during the countdown starts clean. Each start light is beeped so the start can be timed by ear; sparks show every charging kart's tier, orange for the weak boost and red for the full one, with no warning once the hold has tipped into a stall. The snapshots carry each kart's start and stall time left, and a client's prediction adopts the server's verdict.
The scale on a bot's top speed by its spline distance from the nearest human: slower far ahead, faster far behind, between the tuned bounds. The lower bound varies by bot level, up to one at Ace, where a bot ahead is never slowed; the upper bound is the same at every level. A human's kart is never banded.
A lobby identified by a four-letter code from an unambiguous alphabet. Holds up to eight players, has a creator, and moves through Open, Countdown, Racing, Results and Closing. A room enters Closing five minutes after the last human leaves.
The secret a room deals a player at their join, which takes their seat back over a new connection. Mid-race a bot drives the kart of a Disconnected player until the token rejoins or the race ends; the seat, and the token with it, is freed at the results. A seat an Open room brings back after a server restart waits Disconnected for its token too, and frees after the tuned grace if it never comes.
The player who can press Start in a room. The role passes to the next player if the creator leaves, so a room never gets stuck.
One fixed step of the sim, 60 per second on both client and server. Every rule in the game is expressed per tick, never per frame or per wall-clock second.
The server's authoritative state of every kart at a tick, sent at 30 Hz together with the input sequence applied at that tick per client and the events since the previous snapshot. Its per-kart part is the kart readout, as the server's sim reads it (ADR 0090).
An ordered gate on the track used for lap counting and wrong-way detection. Spaced evenly round the lap, twelve on the oval and fifteen on Bell Deer, Goldstone and Monarch, each reaching the walls' outer faces, so a kart between the walls or in the air over one crosses every one in order (ADR 0079). A kart that leaves the world, or ends up behind a wall, respawns at its last checkpoint facing the next one (ADR 0063); a kart that misses a checkpoint is not respawned and drives back through it (ADR 0022).
Distance along the track centreline to the nearest centreline point within reach of the last reading, so a kart keeps its own leg where the course crosses over itself. Race position is ordered by lap, then checkpoint index, then spline progress. Decreasing spline progress for two seconds triggers the wrong-way warning.
What the sim says of one kart at a tick: its transform, speed and velocity, drift and the mini-turbo tier it has charged, item slot, the coins it carries, spin-out, hop, trick, pit lane, boost, slipstream, rocket start and stall, and its place in the race. The sim reports one per kart every tick, and a snapshot carries it as it is; a reading worked out from others, such as the mini-turbo tier, is not carried but worked out again (ADR 0090). A prediction's kart adopts the snapshot's but for the boost and the hop, which it keeps its own. The View, the Instrument panel and the bots read it. Not a snapshot, which is the server's message about every kart.
Where a kart is in the race: its race position, laps completed, last checkpoint crossed in order, spline progress, lap time, best lap, finish time once it has finished and whether the wrong-way warning is up. The sim reports one per kart every tick; the Instrument panel shows the local kart's, and the Results Scene lists every kart's once the race is Finished. Finishers hold their places in finishing order whatever they do after the line.
How one kart answers its controls each tick: its speed, the hop, drift and mini-turbo, boosts, the off-track cap, the freeze of a stall or spin-out, and the hold of a wall and the bump off another kart. One rule in the sim, run for every kart before the physics solver and told afterward of the walls and karts it met.
A short jump (0.3 s airtime) that starts a drift when it lands while the kart is steering above 40 percent of top speed. It lands once the airtime has run out and the kart is back on the road, later where the road falls away under it; a press in the air does not hop again.
A slope laid across part of the road, bounded in metres left of the centreline, that drops away at its lip so a kart flies off it. The road beside it stays flat, so a ramp is a choice of line. Not an elevation feature, which lifts the whole road, walls included.
A hop pressed as a kart leaves a ramp's lip: within 0.1 s either side of it, by the kart's own speed, on the ramp's half and off the top of the slope. The press hops the kart off the slope or, once it is falling off the lip, only counts. The landing pays a small boost, the orange mini-turbo's; a boost under way with more speed left in it stays. A drift's charge is left as it was. Ace bots trick. Its tell is the flourish, the driver's head spun one whole turn about the neck (ADR 0102).
Sliding through a corner after a hop. The drift direction is fixed at the hop; counter-steer widens the arc and inward steer tightens it, as does a brake drift. Holding a drift charges a mini-turbo.
Braking during a drift: the brake tightens the drift's turn on top of the steer, in proportion to how hard it is held, and the mini-turbo keeps charging. It still slows the kart, so held too long it takes the drift under 40 percent of top speed, which ends the drift and loses its charge.
The boost released at the end of a long enough drift: orange at 0.3 s of drift (0.6 s boost), red at 0.6 s (1.0 s boost), both at +30 percent top speed. Shown by sparks at the wheels while charging, orange then red, and on release by a flame at the exhaust in the tier's colour.
The pull of the kart ahead: a kart that holds another's wake for 1 s is towed. No item and no button; open to every kart and every bot, so a race stays close without the item table doing all the work. The server alone judges it; a client's prediction takes its kart's charge and tow from the snapshots (ADR 0077). The own kart feels it as wind lines building through the charge and a whoosh as the tow takes; other karts show nothing.
The 12 m straight behind a moving kart, 1.2 m either side of its travel, that the slipstream is judged in: a kart whose centre lies there, travelling within 0.5 rad of the leader's travel, is in the wake, airborne or not. A kart under half the tuned top speed, such as one spun out or stopped, leaves none. Travel is the body's velocity, so a drifting leader's wake lies along the road. Two wakes at once count as one.
What a full charge in a wake earns: the kart's top speed cap raised 15 percent, to 34.5 m/s with no coins, held at its full 1 s every tick the kart stays in the wake and running down from the tick it leaves. A cap and not a boost: the kart ramps up to it, the brake still works, a mini-turbo or a pad under it fires and sets its own speed, and the kart then settles back to the towed cap, not the plain one. The off-track cap still wins. A spin-out, a respawn and a star's run clear it.
One of a track's fixed pickup spots, from the sidecar: eight on the oval and twelve on Bell Deer, Goldstone and Monarch, in rows of four across the asphalt. A kart whose centre is on a box picks it up, whatever it holds; the box is gone for three seconds and comes back. With an empty item slot the kart rolls an item into it; with an item rolling or held, it gets nothing, so a kart in front denies boxes to the karts behind (ADR 0068). Every pickup is a server event naming the box, so every screen hides the same one.
A pickup lying on the asphalt, from the sidecar: twelve on the oval and fifteen on Bell Deer and Monarch and thirteen on Goldstone, in lines along the straights, ten of them on the centreline. Also the count a kart carries, from none at the lights to a full purse of ten. A kart whose centre is on a coin takes it unless it is spun out; with a full purse its count holds, but the coin is still gone, so a kart in front denies it to the karts behind. A taken coin is gone for three seconds and comes back. Each coin carried raises the kart's top speed by 1%, so a full purse cruises at 33 m/s, and every spin-out costs three, or all the kart has; lost coins vanish, and the View sprays them out of the kart, where nothing can pick them up. The server holds the count: a pickup and a loss are server events, and the snapshots carry the count and the coins there to pick up (ADR 0056, ADR 0067).
A kart's wheel, the rubber the tyre marks and the tyre gauge are named for. Not a coin, which is the pickup, nor a tyre wall, which is a surface.
A kart's one place for an item: a boost, a hazard, a homing projectile, a star or an Air Horn. It is empty, rolling or held. A box into an empty slot starts a roll that lands the item 2.5 s later; until then a press fires nothing and is not remembered, and nothing stops the roll early (ADR 0070). Rolling or held, the slot is full: the kart still takes boxes but gets nothing from them. A press of the item button fires a held item and empties the slot. Every fire is a server event; the Instrument panel shows the local kart's slot, with the fire predicted from the press until the server's event confirms it. While the local kart's item rolls, the slot runs the reel: the items scrolled up through it, slowing to a stop on the one that lands, a click on each change. Other karts' rolls show nothing.
The item a pickup puts in the slot, drawn on the sim's RNG with weights by the kart's race position band: the leaders mostly hazards, the back of the field mostly homing, the star only from third place back and the Air Horn mostly at the front and the middle. Drawn at the pickup, it rolls in the slot for 2.5 s before it lands and can be fired (ADR 0070). Only the server rolls; a client's prediction never picks up a box and holds what the snapshots say.
The defending item. Fired, it drops 1 m behind the kart, on the surface; with the item button held it trails there until the button is let go. It spins out the first kart to reach it and is used up, never the kart that dropped it until that kart has driven clear of it, and a dropped hazard is gone after 30 s. Every snapshot carries the hazards on the track; a client draws a trailed one behind the kart as it draws that kart.
The attacking item. Fired, it chases the kart next ahead of its owner by race position: along the spline at 1.6 times top speed, steering for a point ahead on the centreline, and straight at the kart once within lock range. Reaching the kart it is used up: on a hazard the kart trails, which goes with it, else on the kart, which spins out. Fired by the leader, with no kart ahead, it is wasted. Every snapshot carries the projectiles in flight; a client draws them between snapshots as it draws the other karts.
The comeback item. Fired, it gives the kart a run of 6 s: its top speed cap raised a quarter, with the boost item's kick on the fire, immune to hazards, projectiles and the runaway wheel, and spinning out every ordinary kart it touches, which it passes through; two star karts bump as usual. A mini-turbo or a pad during the run sets its own speed, then the kart settles back to the star's cap; braking still works. A respawn keeps the timer and the finish ends it; a second star puts it back to 6 s. Every snapshot carries the seconds left, which every client shines the kart from through the rainbow in the same phase, and plays the star music to (ADR 0075). In the slot it is a faceted mirror ball on a chain, shining once landed.
The item worth saving. Fired, it lets off one blast 7 m round the kart, reaching only within 15 m of spline progress the shorter way round the lap, so it never reaches through a crossover or across a barrier. Every other kart in reach spins out, unless it trails a hazard, which is used up in its place, or is a star kart or already spun out, which it leaves alone; every hazard lying on the road in reach is used up, the firer's own included, though not one the firer trails; every homing projectile in reach is used up, whoever it chases. The wheel, the boxes and the coins are not touched, and with nothing in reach the blast still fires. Every blast is a server event each client acts on: a flat orange ring grows on the road to the reach, and the blast is heard by distance (ADR 0076). The drone warning goes with it: a marker beside the slot and a rising beep while a homing projectile chasing the own kart is within 40 m, so the blast can be timed to meet it. In the slot it is a grandstand air horn, scowling.
A kart stopped and spun by an item, a star kart or the runaway wheel for a fixed time (1 s): dead to its controls and moved by nothing until the time runs out. Every spin-out costs the kart three coins, or all it carries. Every spin-out is a server event, and the snapshots carry the time left; clients only show it.
The velocity a kart carries away from a kart or tyre wall it touched, decaying over a fixed time (0.3 s to a third) and then gone. A tyre wall gives one as a kart standing still would, with the whole of the bounce to the kart. A wall gives none: it holds the kart at the corner that met it, with no bounce. The handling adds it to the kart's own velocity every tick, so a touch throws the pair apart instead of letting one push the other along; the kart that drove in loses speed and the kart hit keeps its own. A new bump replaces one under way, never adds to it. A contact never turns a kart: only steering does. Resolved on the server; the client's prediction runs the same rule against the other karts' kinematic stand-ins, and a snapshot carries each kart's bump, so a rewind takes the server's bump in place of the prediction's own.
The palette that tells one kart from another, borrowed from a team's colours: primary, secondary and accent, the three the kart is painted in, and a key colour for every single-colour use (the minimap, swatches, kart labels). Eight liveries, assigned in room join order; each comes with its slot's driver.
The client replacing its predicted state with a snapshot and replaying the inputs the server has not yet acknowledged. The visible correction is blended over up to six frames rather than snapped.
How the client draws the other karts: between the two snapshots it has received either side of a render clock 100 ms behind the newest, never past the newest. The own kart's prediction meets them there as kinematic bodies it cannot push.
A race as {seed, track, bots, picks, inputs[]}, the picks written as
fields of the file's own: enough to rerun it anywhere, as the picks it
names.
Inputs are run-length encoded into segments, one input per human kart in
grid order for a run of ticks; the bots drive themselves from the seed. A
replay committed under assets/replays with the state hashes it reported is
a fixture of the determinism gate.
A platform-independent hash of everything in the sim that influences future ticks. A replay reports it after every 60th tick; the native and wasm builds must report the same values for the same replay.
A track as players see it: its name, its flag and the real circuit it is drawn after, such as Goldstone, after Silverstone. The creator picks the course on the Title Scene and it is fixed for the room (ADR 0061). The oval is a track but no course.
The data file exported from Blender next to a track's glTF: the centreline, checkpoints, item box and boost pad positions, the spawn grid and the tagged collision meshes. The sim reads the sidecar and never the glTF.
What is under a point on the track: asphalt, sand, grass, wall, tyres, or out of world when nothing is below it. Collision meshes in the sidecar are tagged with the first five; the sim answers with the topmost one under a point.
The barrier along each edge of the run-off, the whole way round every track but for the gaps at a pit lane's fork and merge, whose outer wall takes over: the track limit. A kart can leave the asphalt for the sand but never the course, so no corner can be cut and no checkpoint skipped. A wall holds a kart at the corner that met it, with no bounce (ADR 0022). It stands 6 m off the asphalt on Bell Deer and Goldstone and 2 m off it on Monarch (ADR 0064).
Where a course crosses itself: one leg rises on an embankment and crosses the other on a deck, between its own walls, and the other leg runs beneath it through the underpass, at ground level. The deck, its embankment and abutments are scenery; a kart rides the raised leg's own asphalt and sand, and reads its spline progress near its last reading so it keeps to its own leg through the crossing (ADRs 0046, 0047).
Scenery a layout declares in its decor and the builder places beyond the walls: in the glTF only, never in the sidecar, so karts never touch one and the sim never learns it exists. A prop that must stop a kart becomes a wall or a tyre wall with its own ADR. A moving prop is moved by the View from its own clock, as Presentation (ADR 0050).
A patch of trees of one kind, pine, round or cherry, that the builder scatters over a disc or along a line from a count and a seed. The count is a cap: a tree within 3 m of a wall or 5 m of another is dropped, so no tree is ever placed by hand, and the seed makes every export scatter the same trees. A prop (ADR 0050).
The Ferris wheel outside Bell Deer's first curve: a prop whose rim and sixteen gondolas are nodes of their own in the glTF, which the View turns from its own clock, each gondola turned back so it hangs level. It carries no name (ADR 0050).
The tyre-shaped ring across the middle of Bell Deer's Dunlop curve: a prop a kart passes under on the climb to the boost pad, lettered with its sponsor round the belt on both faces. A span, so it is held to the span rule, not the 8 m one: its underside keeps the gantry's 7 m over the asphalt and its feet stand on grass beyond the walls (ADR 0050).
The row of garages beside the start straight, which the grid faces through the countdown: a prop with a door and a flag in each livery's key colour and no number on any door (ADR 0035). Its doors face the pit boxes where a course has a pit lane (ADR 0081). Inside Bell Deer's straight; inside Goldstone's, white (ADR 0089); right of Monarch's, across from the stands (ADR 0088).
Monarch's roof over about 150 m of the tunnel bend: a side against the back of each wall from the grass to the roof, the roof's underside 6 m over the road so the chase camera passes under it, and a lamp every 12 m along each side. Scenery only; the walls under it hold the karts (ADR 0064).
The row of five airfield hangars outside Goldstone's Hangar Straight: a prop of barrel-roofed sheds, each with a dark door in the gable toward the track, held to the 8 m rule like the pit building (ADR 0060).
The open hangar Goldstone's Hangar Straight drives through, beside the middle of the hangars' row: a prop that spans the road like the arch, a side on the grass beyond each wall and a barrel roof between them, steel ribs at a 6 m pitch under its dark underside, and two light aircraft parked on its floor right of the track. Held to the span rule; its presentation zone shades the light and echoes the engine under it.
Goldstone's landmark where the Wellington Straight points, past Brooklands and Luffield: a prop of a square shaft under a wider glazed cab and a banded mast, held to the 8 m rule and kept in every chase camera's view down the straight.
The SLIPSTREAM AIRWAYS airship over Bell Deer's east infield: a prop that flies, so it has no footprint, a single node in the glTF with its origin at the nose, which the View flies once round its circle every four minutes from its own clock, nose along the tangent, its lowest point 30 m over every road under it. Its sponsor rides on both flanks as children of the node (ADR 0050, ADR 0038).
The BOX BOX BOX LOGISTICS helicopter over Monarch's harbour: a prop that flies, like the airship, so it has no footprint. Its body is a node in the glTF with its origin at the nose, which the View flies anticlockwise once round its circle every two minutes from its own clock, nose along the tangent and dipped 5 deg; a main rotor and a tail rotor hang under it as nodes of their own, which the View spins, and its sponsor rides on both cabin flanks. Its lowest point keeps 30 m over every road under it (ADR 0050, ADR 0038).
The three red jets over Goldstone's hangars: a prop that flies, like the airship, so it has no footprint. The whole formation, each jet's smoke ribbon included, is one node in the glTF with its origin at the leader's nose, which the View flies nose first along a 600 m pass over the hangars, its flypast, against the race, in 6 s, and hides between passes. Each pass is cued as the own kart reaches Chapel, so the formation is over the hangars as the kart runs down the Hangar Straight, with a roar that swells to it. Its lowest point keeps 20 m over every road under the pass (ADR 0050, ADR 0099).
Monarch's basin of sea water outside the harbour straight and the pool,
close behind their stands, and round the quay and Rascasse: a prop of flat
water a hair over the grass inside a raised stone quay, with yachts moored
stern-to along the quays near the lap. The yachts and the water stay still;
only its spray moves, bursts the View raises over the quay beside quay now
and then from its own clock. It is held to the 8 m rule (ADR 0050).
The grand house outside Monarch's Casino Square, at the crest: a prop of stucco under copper roofs, two towers and a dome, standing on a terrace that rises from the grass to the road's height there, its dark door and windows toward the track. It carries no name, and it is held to the 8 m rule (ADRs 0050, 0065).
A prop of Monarch's town: a hotel or block of flats, terraced, a slab or a hipped villa by its number, its windows toward the track. Up the climb it stands on a terrace at the road's height and keeps out of the chase cameras' sight line to the casino; round the harbour it stands on the grass facing the water. It is held to the 8 m rule (ADRs 0050, 0065).
The pool beside Monarch's pool chicanes, on their outside: a prop of water inside a low deck with lane lines and parasols, nothing on it 3 m tall. It is held to the 8 m rule (ADR 0050).
A stack of tyres standing on the asphalt, tagged tyres. A kart that
hits one takes a bump straight out from it and loses speed by how square
it hit, so a glancing touch keeps nearly all its speed and a square hit
sends it back the way it came, slower. It never holds a kart and never
spins one out (ADR 0041).
A raised kerb on the inside of a corner's apex. A kart on the ground that drives onto it is launched into a hop that lands straight, losing a share of its speed and any drift under way with its charge (ADR 0041).
A loose wheel that rolls in across the track on a fixed cycle of the race clock, with the marshal waving hazard flags for a second before each pass and through it, bounces twice off the walls, landing somewhere the race seed picks each time, and rolls out through the far wall. A kart it reaches spins out, by no one (ADRs 0041, 0042, 0045).
The figure on a marshal post beside a runaway wheel's crossing. While the wheel is quiet he sits with a cup of tea; from the flag going up, a second before a pass, to the end of it he is on his feet waving two hazard flags, and while the wheel rolls he hops. Presentation only (ADR 0045).
One of the two flags the marshal waves: yellow with black diagonals, not a racing flag. Nothing to do with the item called a hazard (ADR 0045).
The paint over a runaway wheel's crossing: wall to wall and as far along the track either side as the wheel can reach, yellow and black chevrons across each end and a light yellow tint between. It flashes red from the flag going up to the end of the pass. Paint only: not a surface, and not the item called a hazard.
One screen of the client with its own lifecycle: Title, Room, Race, Results. Exactly one Scene is active at a time.
The part of a Scene that renders the world. The Race Scene has one View, the 3D track, drawn by Three.js from kart transforms the bridge reports.
The HUD overlaid on a View: position, lap, lap time, best lap, item slot, speed, gear, coins and tyre, the BOX call, wrong-way warning, connection banner, the start lights over the View and the course map. Reads state; never drives it.
A readout's chamfered backing on the Instrument panel: a lit, a mid and a shaded band of one colour, over the ink drop, with no outline (ADR 0037). Carbon for most readouts, the item box gold for the item slot and a kart's key colour for its label. The position is not a plate of its own: it is a band in the local kart's primary inside the timing tower's plate.
The position, lap, time and best above the item slot as one carbon plate, as a broadcast draws them: the position as a band in the local kart's primary at the top, then the lap, time and best rows sharing a label column, with hairline rules between the rows and one straight right edge. 26 HUD units wide on every race, so the lap row holds five lap flags (ADR 0105).
The Instrument panel's reading of the local kart's speed as a gearbox: six even bands up to top speed, N while the speed shows as 0 km/h, R while reversing, 6th held on the limiter over top speed, and PIT in the pit lane. Worked out in the client from the kart readout's speed; the sim has no gears (ADR 0031).
The row of twelve lights over the gear, lit green, red then blue in thirds as the revs in the gear climb to the shift, all blue on the limiter. Decorative: the gear and the speed are the text.
How much life a kart's tyres have left, as a percentage: 100% is new and 0% is gone. It falls as the kart is driven and only a stop raises it. The Instrument panel's tyre gauge shows it on the local kart drawn from behind, its tyres green above 60%, yellow above 30% and red at 30% and below, read rounded up so 0% means truly gone (ADR 0080). With Tyres Off it holds at 100%. Avoid: tyre wear, for the number. As it falls it costs speed and grip by ADR 0080's tables, as ADR 0087 and ADR 0095 steepen them, steepest from the cliff at 30%; a boost runs at its share of the worn cap. Under the cliff a kart trails light tyre smoke and lays darker tyre marks.
How far worn tyres let a kart's line of travel slide wide of its facing past a cornering limit: none from 60% tyre life up, 0.05 rad at 30% and 0.15 rad at 0%, on top of any drift's slip. It builds over a few ticks, with no random twitch (ADR 0080).
The radio's call to come in for tyres: BOX BOX on a plate beside the tyre
gauge and a chime, from 120 m to 15 m short of the pit lane's fork while tyre
life is at 30% or below, every lap the kart stays out. Down in the pit lane,
and not on a course without one nor on the final lap (ADR 0096).
Whether a race's tyres wear: On or Off, one of the picks on the Title Scene, fixed for the room as the course is and shown on the Room Scene (ADR 0083). Off is the race as it was before there was tyre life, and what a kept room or a replay without a pick is. A replay carries it.
Whether rain comes in a race: Dry or Rain, one of the picks on the Title Scene, fixed for the room as the course is and shown on the Room Scene (ADR 0103). Dry is the race as it was before there was weather, and what a kept room or a replay without a pick is. A replay carries it.
What Rain brings: from the first tick any kart starts the lap the seed picks, the whole field's grip falls with the wetness and stays down to the flag. It never touches the top speed, the wear rates or the mini-turbo charge, and there is no wet tyre (ADR 0103). Clouds gather over the leader's last quarter of the lap before, changing only the look, and the look then follows the wetness on every screen: the sky greys through the View's light scale, the asphalt darkens with a soft sheen while kerbs, white lines and boost pads keep their colours, spray and streaks fall, a RAIN plate shows as it arrives and a rain bed plays under the SFX toggle.
The low pale plume at a wet kart's rear wheels: no higher than their tops and about two kart lengths long, so wings, helmets and liveries stay visible through a pack. It thickens with the wetness and comes only off moving tyres on the road. Not the coins a spin-out sprays, and not worn tyres' darker, rising smoke.
The rain falling round the camera, thrown ahead of it. A roof stops them through presentation zones, though the grip stays wet there, and a viewer who asks for less motion gets fewer.
The rain's sound: a loop under the SFX toggle, levelled by the wetness and never pitched, the same under a roof.
How wet the track is, from 0 at the tick the rain began to 1 twenty seconds on, then held; it scales one row of grip factors on top of the tyres'. The sim holds the tick it began and the snapshot carries it to the prediction.
What the Race Scene reads of a race once a frame, as of the last tick: every kart readout and standing, the phase, the local kart's item slot, the item boxes and the coins there to pick up, the hazards, the projectiles and the wetness. A solo race reports it from the sim in the browser and a room's race from the server's snapshots and events; the View, the Instrument panel and the audio each read the one readout. Not a snapshot, which is the server's message.
The track's outline seen from above in a corner of the Instrument panel, drawn from the sidecar's centreline as asphalt between white walls with a chequered start, and a faceted octagon marker per kart in its key colour at the transform the View draws that frame. At a bridge the deck is drawn over the road beneath, so the map reads as a crossing rather than an X. The own kart's marker is larger and ringed in white. The map is fixed: it never rotates with the own kart.
Everything the player sees and hears that is not a rule: meshes, materials, particles, camera motion, audio. Presentation never changes sim state.
A stretch of a course, by spline progress, where the View's light and the audio's ambience and crowd change for the own kart: it eases in, holds and eases out between four edges, and may run over the start line. Keyed by spline progress, never by position, so at Bell Deer's bridge the leg the kart is on decides. Monarch has two: the tunnel, darker, with the engine echoing and the lamps' warm light passing over, and the harbour after it, brighter, with the water and the stand's crowd. Bell Deer has one on each leg of its bridge: under the deck on the underpass, darker and echoing, and up the embankment over it, brighter. Goldstone has one under its hangar shell, shaded and echoing. The three that pass under something also hold a roof, which stops the rain's streaks. A client table per course (ADR 0098); Presentation only, so it changes neither grip nor timing.
A piece of Presentation tied to one mechanic so the mechanic has a visible or audible tell: tyre marks on drift, sparks on mini-turbo charge, a dust puff off-track, a spin animation on spin-out, beeps on the countdown and sparks on a rocket start's charge, a sputter and dust at the wheels on its stall, a shadow disc on the road under each kart so a hop's height reads, the driver's flourish on a trick, and on every boost a flame at the exhaust and, for the own kart, wind lines and a wider field of view; and on the runaway wheel, flames off its back, a smoke trail, dust where it lands and sparks off each wall it rebounds from; and under 30% tyre life, light tyre smoke and darker tyre marks.
The driver's head rolling at the neck against the lateral G of a turn: turn left and the head tips right, further the harder the turn up to a cap. The head holds level through a spin-out or a stall. Presentation worked out in the client from two kart readouts; the sim has no head.