Glossary
In short
One line per term. Follow the link for the full rules and numbers.
Game terms
| Term | Meaning | Note |
|---|---|---|
| $$$ ball | Sandlot’s special ball: a home run off it pays +3 coins | Special Balls |
| 100% | Beating a map on Hard | Map Select and Unlocks |
| Account level | Max 50; gates which batters and cosmetics you can buy and which call signs you can wear | XP and Levels |
| Aerial target | A target with height above 0; the ball has to fly through it | Moon Stadium |
| Aim helper | See-through gold bat outline on the mouse aim; the gap between its two curves is the sweet spot. Replaced the aim ring in #46 | Batting Feedback |
| Arc | A pitch’s mid-flight loop in metres; curveballs and changeups can loop sideways | Pitch Types |
| Ball four | Four balls only reset the count; there are no walks | Count and Outs |
| Batter modifiers | Stat penalties from a park or boss that apply only during the at-bat | Stats |
| Batting cage | Endless practice with no saves or rewards; Tab changes the pitch, M the park | Batting Cage |
| Batting style | A batter’s trajectory (low / mid / high), hit direction (pull / push) and curve | Batting Explained |
| Big moment | A home run that earns the full replay: a replay-worthy swing, a long shot, a target or the scoreboard | Hit Show |
| Boss ball | A boss’s own special ball; it stacks with the map’s ball and sets the look | Pitchers and Bosses |
| Bonus location | A target that adds flat points (+50 to +200) instead of multiplying | Moon Stadium |
| Boss inning | Innings 3, 6 and 9: a boss pitcher, goal x1.25, +5 coins. Inning 9 is the park’s own boss | Run Structure |
| Break | How far a pitch moves by the plate; grows with t², so it bends late | Pitching |
| Call sign | A free title over your batter’s name, opened by account level | Call Signs |
| Carry distance | Distance to where the ball first lands; used for scoring | Hit Physics |
| Character level | Max 10 per batter; trait perks at levels 2, 5 and 10 | XP and Levels |
| Checkpoint | run.json, saved on the map and shop screens, used by CONTINUE | Run Structure |
| Coins | Currency earned and spent inside one run | Shop and Economy |
| Co-op | 2 to 4 players take turns batting in one shared run, refereed by the host | Co-op Overview |
| Contact (stat) | Adds 0.12 m of hit radius per point (base 1) and widens the contact zones | Stats |
| Contact zone | Where on the bat the ball is hit: perfect (within 0.04 m of the sweet spot), nice (to 0.11 m), sour (further). Sets the grade | Batting Explained |
| Cutscene | Match intro before inning 1; BOSS DOWN!, MAP BEATEN!, GAME OVER at the end. Settings > CUTSCENES turns them off | Cutscenes |
| Decoys | The Phantom’s fake balls: they split off at 30% of the flight and cast no shadow | Pitchers and Bosses |
| Cosmetic | A look-only item: hat, glasses, shoes, bat | Customization |
| Daily challenge | A seed from the UTC date, a seed-picked map, always Normal; unlocks nothing | Daily Seed and Leaderboard |
| Difficulty | Normal / Medium / Hard per map: goals, pitch speed, special balls, prices, outs, points | Difficulty |
| Dressing | The props around a park, from a baked prefab or a code layout | Ballpark Building |
| Equipment slot | Bat, Glove, Cleats hold one item each (buying replaces); Charms stack | Upgrades and Synergies |
| Extra Outs | Stat added to the 3 outs per inning (Hard: −1) | Count and Outs |
| Final boss | A park’s own boss for inning 9 (finalBossId): Benny, Fitz, Gale, Phantom, Alien | Pitchers and Bosses |
| Foul | Contact with spray beyond ±45°; a strike, but it can’t be strike three | Count and Outs |
| Grade | WEAK / GOOD / GREAT / PERFECT, from where on the bat the ball hit (not timing) | Batting Explained |
| GREEN | A perfect-zone hit that is also on time (timing ≥ 0.80, within 9° of dead centre) | GREEN Swings |
| Hit aim | A/D (PULL / OPPO) and W/S (LIFT / DRIVE) held at contact | Batting Explained |
| Hit counter | The live feet counter and home run score stack during the flight | Hit Show |
| Green streak | Greens in a row; takes don’t break it, any non-green swing does | GREEN Swings |
| Hit radius | How far the ball can be from the bat axis and still be hit; 0.19 m at base stats | Swing and Timing |
| Hit stop | A brief freeze on contact: 0.09 s for GREAT or better, 0.16 s for GREEN | At-Bat Loop |
| Home run | A fair ball that clears the wall on the fly | Hit Physics |
| Inning | One step of a run: a pitcher and a score goal | Run Structure |
| Inning goal | The score that clears an inning, rounded to 25 | Run Structure |
| Instant replay | Slow-motion close-up of contact after a GREEN or a well-timed PERFECT; big moments get a full replay after the play | Hit Show |
| Match intro | Broadcast-style opening before inning 1, ending in the batter’s walk-up | Cutscenes |
| Level perk | A small trait boost for a batter at character levels 2, 5 and 10 | Batters |
| Meta points (PTS) | The currency kept between runs | Meta Progression |
| Minimum round | minRound: the earliest inning (0-based) a pitcher can appear in | Pitchers and Bosses |
| Mini-round | A co-op turn, played as an at-bat round that starts from the team score | Co-op Run Flow |
| Opener rotation | Co-op inning r opens with seat r mod players | Co-op Rules |
| Outfield target | A zone past the wall that multiplies a home run’s score | Scoring |
| Outs pool | Co-op shared outs per inning = max(outsPerInning + difficulty delta, i.e. 3 or 2 on Hard, players still in); Extra Outs don’t add to it | Co-op Rules |
| Perk | A locked upgrade bought with points on the PERKS screen | Meta Progression |
| Pitch lean | Pitchers throw the pitch types a special ball rides on 80% of the time | Pitchers and Bosses |
| Pitch mix | A pitcher’s weighted list of pitch types | Pitchers and Bosses |
| Play card | The panel after each pitch: headline, grade, MPH, LAUNCH, FT and TIMING: EARLY / LATE / ON TIME | Batting Feedback |
| Points gem / coin icon | Purple gem = meta points, gold coin = run coins | Shop and Economy |
| Pitch speed scale | 0.6 × the difficulty’s speed; shortens flight time, not the mph shown | Pitching |
| Practice park | A park used only in the batting cage (practiceParks), never in runs | Scoreboard Smash |
| Quality | 0..1 from the contact zone only (perfect 0.9+, nice 0.45–0.9, sour 0.2–0.45); sets the grade | Batting Explained |
| Rarity | Common / Rare / Epic; shop weights 6 / 3 / 1 | Shop and Economy |
| READY | Co-op shop button; the host continues when everyone is ready | Co-op Run Flow |
| Required level | The account level needed before a batter or cosmetic can be bought | Batters |
| Reroll | Pay to redraw the shop offers; costs 2, +1 each time per visit | Shop and Economy |
| Run | One map, up to 9 innings, at one difficulty | Run Structure |
| Second life | Co-op: Extra Outs > 0 gives you 2 outs on your own turn | Co-op Rules |
| Sky preset | ClearDay, Overcast, Night or Space, applied by SkyBuilder | Rendering |
| Special ball | A park effect on some pitch types, rolled on its own seeded stream | Special Balls |
| Starting kit | The upgrades a batter owns at the start of every run | Upgrades and Synergies |
| Strike zone | x ±0.22 m, height 0.5–1.1 m on the plate plane, plus the ball’s radius | Pitching |
| Synergy | A bonus that switches on once enough owned upgrades share a tag | Synergies |
| Take | No swing: a pitch in the zone is a strike, one outside is a ball | Count and Outs |
| Tracer | Glowing arc along the flight, coloured by distance | Hit Show |
| Target | A landing zone or aerial point that multiplies or adds to a home run’s score | Scoring |
| Timing ring | Optional ring (Settings: TIMING RING, off by default) that shrinks to the best press moment: white / yellow / green | Swing and Timing |
| Timing Window (stat) | Base 0.11 (shown as “110 ms”); scales the hit radius by √(TimingWindow / 0.11). Not a time window in seconds | Stats |
| Turn | Co-op: one player bats until they make an out; costs the pool 1 out | Co-op Rules |
| Unlock order | The order of the ballparks list: which map opens next, and goals x1.15 per step | Map Select and Unlocks |
| Whiff | A swing that never touches the ball; counts as a strike | Count and Outs |
| Wobble | The knuckleball’s side-to-side flutter, in metres | Pitch Types |
Code and tooling terms
| Term | Meaning | Note |
|---|---|---|
| App 480 (Spacewar) | Valve’s test app id used until the game has its own | Steam Test Guide |
| AtBatPose | Unreliable 41-byte spectating pose message, 30 per second | Net Messages |
| CoopRules | The host’s pure referee logic, tested headless | Co-op Rules |
| CoopRun | The co-op IRunDriver on each machine | Co-op Run Flow |
| CoopWatch | Game state while someone else bats | Live Spectating |
| Dev folder | Desktop\Code\HomeRunDerby, the folder Claudio playtests in | Git and PRs |
| finalBossId | The park field naming who pitches the last inning | Add a Final Boss |
| Headless compile check | Running UrpSetup.Run with the Editor closed, then reading Logs/Editor.log | Testing |
| HOMERUNDERBY_STEAM | Scripting define that compiles the Steam code in | Transports |
| Host | Player 0: owns the roster, referees turns, relays the batter’s messages | Lobby and Session |
| Join code | The port (7777) on LOCAL, the Steam lobby id on STEAM | Transports |
| LocalTransport | UDP with its own reliable channel, for one PC or a LAN | Transports |
| MsgId | First byte of every net message: 1-2 ping, 10-16 lobby, 30-36 run, 40-44 spectating | Net Messages |
| NET TEST | Dev overlay (Ctrl+Shift+N) for raw HOST / JOIN / PING | Steam Test Guide |
| NetSession | The lobby layer: roster, version check, StartRun, routes message ids 30 and up | Lobby and Session |
| NetSession.Protocol | Co-op protocol string (now HRD-COOP-3); mismatched builds are refused | Protocol Versions |
| One id namespace | unlockedIds is shared by batters, upgrades and cosmetics | Add an Upgrade |
| Protocol bump | Changing NetSession.Protocol when co-op messages or rules change | Add a Net Message |
| Reference worktree | HomeRunDerby-main, a git worktree on main used as a read-only copy | Git and PRs |
| RunConfig | The global numbers for a run: innings, goals, coins, shop | Run Config |
| Self-test | An Editor static Run() from Tools → Home Run Derby; logs PASSED / FAILED, exit 0 / 1 in batch mode | Testing |
| SpectateFeed | The spectator’s playback buffer: offset = fastest delay + 0.15 s | Live Spectating |
| StatModifier | A change to one stat, either Add (flat) or Percent | Stats System |
| SteamTransport | Friends-only lobby plus Steam Datagram Relay | Transports |
| BeanToon | The toon shader every object uses | Rendering |
| CharacterFitProfile | Hand-tuned cosmetic sockets for one character model | Fit Mode |
| CosmeticAnchor | Bone plus local pose and size where a cosmetic hangs | Characters and Rigs |
| FitOverrides | JSON fit values applied on top of the assets at boot | Fit Mode |
| GameBootstrap | Spawns the game after any scene loads, so no scene setup is needed | Boot and GameRoot |
| GameEvents | Static event bus: gameplay raises, UI / audio / effects subscribe | Game Events |
| GameRoot | Composition root: creates every service and holds the GameState | Boot and GameRoot |
| GameState | The current screen; UIRoot draws one IMGUI view per state | Game States and Screens |
| IBatterFigure | The batter figure contract (HumanBatter, BeanBatter) | Characters and Rigs |
| Insta-home-run bat | Dev menu toggle that makes every swing a no-doubter | Dev Menu and Shortcuts |
| IRunDriver | What the in-run screens talk to: RunManager (solo) or CoopRun | Architecture |
| Park dressing | Visual props around a park, from a baked prefab or a code layout | Ballpark Building |
| PlayerStats | Sums modifiers: (base + adds) × (1 + percents) | Stats System |
| Rigged bean | A Blender bean model made Humanoid at runtime by BeanRig | Characters and Rigs |
| RunSaveData | The run.json checkpoint: seed, choices, totals | Save System |
| ScoreboardHit | Event raised when a ball smashes the scoreboard | Scoreboard |
| SeededRandom.Derive | Mixes a seed and a stream id into an independent seed | Seeds and Determinism |
| ShopSalt | Per-player co-op salt so each player gets their own shop offers | Seeds and Determinism |
| Stream id | A fixed number giving one system its own RNG stream | Seeds and Determinism |
| Toonify | Swaps an imported model’s materials for toon copies | Rendering |
| TurnSeed | Co-op pitch seed for one turn of an inning | Seeds and Determinism |
| BroadcastDraw | The TV-graphics kit shared by the cutscenes and hit show | UI System |
| IndexCatalog | Builds the INDEX screen’s list from the content, plus hand-added planned items | Index Screen |
| IntroGate | Co-op: the host holds the first turn until everyone finishes the match intro | Co-op Run Flow |
| Swing log | swings.csv, one line per pitch, for tuning the batting | Swing Log |
| TEST HITS | Dev menu tool that turns every swing into a chosen kind of batted ball | Dev Menu and Shortcuts |