refactor: extract magic numbers to named constants

Frontend: choreography selection ratios, morph trigger chances,
creator cameo/ultimate chances, dodge/counter probabilities.
Server: HP, K-factors, Elo divisor, tier thresholds, fight loop interval.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/src/game/FightScene.ts

@@ -5,6 +5,11 @@ import { generateSpriteSheet, generateJudgeSpriteSheet, generateHumanSpriteSheet
 import type { Fighter, FightSceneConfig, RoundEvent, FightContext, ChoreoContext } from './fight/types'
 export type { FightSceneConfig, RoundEvent } from './fight/types'
 import { ARENA_THEMES, spriteAnims, CHALLENGE_THEMED, TIER_ULTIMATES, CREATOR_MOVES, CREATOR_ULTIMATES } from './fight/constants'
+import {
+  CREATOR_ULTIMATE_CHANCE, CREATOR_THEMED_MOVE_RATIO,
+  CRIT_THEMED_RATIO, CHOREOGRAPHY_THEMED_RATIO, CHOREOGRAPHY_GENERIC_CUTOFF,
+  TIER_ULTIMATE_CHANCES,
+} from './fight/config'
 import { spawnSparks as _spawnSparks, spawnBulletHoles as _spawnBulletHoles, spawnExhaust as _spawnExhaust } from './fight/particles'
 import { glitchRGB as _glitchRGB, scanlineGlitch as _scanlineGlitch, vhsTracking as _vhsTracking, dimensionalShift as _dimensionalShift } from './fight/effects'
 import { spawnProjectile as _spawnProjectile } from './fight/projectiles'
@@ -46,9 +51,9 @@ import {
 
 
 export function pickChoreography(challengeType: string, isCritical: boolean, _round: number, attackerTier: number = 0, attackerArchetype?: string): string {
-  // THE CREATOR: special move selection — 50% ultimate, 60% creator moves, rest normal
+  // THE CREATOR: special move selection
   if (attackerArchetype === 'the_creator') {
-    const ultimateChance = isCritical ? 1.0 : 0.5
+    const ultimateChance = isCritical ? 1.0 : CREATOR_ULTIMATE_CHANCE
     if (Math.random() < ultimateChance) {
       // Creator gets ALL ultimates + their 4 exclusive ones
       const all: string[] = [...CREATOR_ULTIMATES]
@@ -57,17 +62,15 @@ export function pickChoreography(challengeType: string, isCritical: boolean, _ro
       }
       return all[Math.floor(Math.random() * all.length)]
     }
-    // 60% creator-themed, 40% normal selection
+    if (Math.random() < CREATOR_THEMED_MOVE_RATIO) {
-    if (Math.random() < 0.6) {
       return CREATOR_MOVES[Math.floor(Math.random() * CREATOR_MOVES.length)]
     }
     // Fall through to normal selection
   }
 
   // Tier-gated ultimates: higher tier = higher chance of spectacular ultimate moves
-  // Tier 2: 15% chance, Tier 3: 20%, Tier 4: 30%, Tier 5: 40%
   if (attackerTier >= 2) {
-    const ultimateChance = attackerTier === 2 ? 0.15 : attackerTier === 3 ? 0.20 : attackerTier === 4 ? 0.30 : 0.40
+    const ultimateChance = TIER_ULTIMATE_CHANCES[attackerTier] ?? TIER_ULTIMATE_CHANCES[5]
     // On crits, double the chance
     const roll = isCritical ? ultimateChance * 2 : ultimateChance
     if (Math.random() < roll) {
@@ -85,8 +88,7 @@ export function pickChoreography(challengeType: string, isCritical: boolean, _ro
   // Critical hits always get BIG moves (but can still be themed)
   if (isCritical) {
     const entry = CHALLENGE_THEMED[challengeType]
-    // 50% themed, 50% epic generic for crits
+    if (entry && Math.random() < CRIT_THEMED_RATIO) {
-    if (entry && Math.random() < 0.5) {
       return entry.themed[Math.floor(Math.random() * entry.themed.length)]
     }
     const critMoves = [
@@ -111,11 +113,10 @@ export function pickChoreography(challengeType: string, isCritical: boolean, _ro
     return fallback[Math.floor(Math.random() * fallback.length)]
   }
 
-  // 60% themed, 25% generic fallback, 15% wild card
   const roll = Math.random()
-  if (roll < 0.6) {
+  if (roll < CHOREOGRAPHY_THEMED_RATIO) {
     return entry.themed[Math.floor(Math.random() * entry.themed.length)]
-  } else if (roll < 0.85) {
+  } else if (roll < CHOREOGRAPHY_GENERIC_CUTOFF) {
     return entry.generic[Math.floor(Math.random() * entry.generic.length)]
   } else {
     const wild = [

frontend/src/game/fight/config.ts

@@ -0,0 +1,43 @@
+// ═══════════════════════════════════════════════════════════════
+// Gameplay constants — all tunable magic numbers in one place
+// ═══════════════════════════════════════════════════════════════
+
+// --- Choreography selection probabilities ---
+export const CREATOR_ULTIMATE_CHANCE = 0.5          // Creator ultimate chance (non-crit); 1.0 on crits
+export const CREATOR_THEMED_MOVE_RATIO = 0.6        // Creator uses creator-themed moves 60% of the time
+export const CRIT_THEMED_RATIO = 0.5                // On crits: 50% themed, 50% epic generic
+export const CHOREOGRAPHY_THEMED_RATIO = 0.6        // Normal: 60% themed
+export const CHOREOGRAPHY_GENERIC_CUTOFF = 0.85     // Normal: 25% generic (0.60–0.85), 15% wild (0.85–1.0)
+
+// --- Tier-gated ultimate chances ---
+export const TIER_ULTIMATE_CHANCES: Record<number, number> = {
+  2: 0.15,
+  3: 0.20,
+  4: 0.30,
+  5: 0.40,
+}
+
+// --- Morph system ---
+export const CREATOR_MORPH_CRIT_CHANCE = 0.7        // Creator morphs on devastating crits 70%
+export const CREATOR_MORPH_INTENSITY_THRESHOLD = 0.6 // Creator morphs when intensity > 0.6
+export const BOT_MORPH_CRIT_CHANCE = 0.4            // Regular bots morph on devastating crits 40%
+export const BOT_MORPH_INTENSITY_THRESHOLD = 0.7    // Regular bots morph when intensity > 0.7
+
+// --- Creator cameo ---
+export const CREATOR_CAMEO_CHANCE = 0.06            // 6% per round in non-creator fights
+
+// --- Round exchange probabilities ---
+export const DODGE_CHANCE = 0.12                    // Defender dodges instead of being hit
+export const COUNTER_ATTACK_CHANCE = 0.25           // Defender counters after getting hit
+export const SCANLINE_GLITCH_CHANCE = 0.25          // Random scanline glitch during exchanges
+export const COMEDY_SFX_CHANCE = 0.15               // Comedy sound on non-decisive hits
+export const PHYSICAL_CONTACT_BASE = 0.35           // Base chance for brawl/clinch
+export const PHYSICAL_CONTACT_INTENSITY_SCALE = 0.2 // Added per unit of intensity
+export const PHYSICAL_CONTACT_EXCHANGE_BONUS = 0.15 // Added after first exchange
+export const CROWD_REACTION_CHANCE = 0.4            // Crowd reacts to round results
+export const MAYBE_SHOW_HUMAN_CHANCE = 0.2          // Show human coach
+export const CREATOR_VOICE_LINE_CHANCE = 0.6        // Creator gets a voice line
+
+// --- Hyperdetail (grotesque close-up) ---
+export const HYPERDETAIL_BASE_CHANCE = 0.05         // Base hyperdetail chance
+export const HYPERDETAIL_INTENSITY_SCALE = 0.45     // Scales with intensity

frontend/src/game/fight/rounds.ts

@@ -10,6 +10,15 @@ import {
   sfxDrumRoll, sfxPowerUp, sfxVineBoom, sfxRandomSilly, sfxRandomComedy,
   sfxBoneCrack, sfxSlideWhistleDown, sfxDodge, sfxRandomFail, sfxSlideUp,
 } from '../audio'
+import {
+  CREATOR_MORPH_CRIT_CHANCE, CREATOR_MORPH_INTENSITY_THRESHOLD,
+  BOT_MORPH_CRIT_CHANCE, BOT_MORPH_INTENSITY_THRESHOLD,
+  CREATOR_CAMEO_CHANCE, DODGE_CHANCE, COUNTER_ATTACK_CHANCE,
+  SCANLINE_GLITCH_CHANCE, COMEDY_SFX_CHANCE,
+  PHYSICAL_CONTACT_BASE, PHYSICAL_CONTACT_INTENSITY_SCALE, PHYSICAL_CONTACT_EXCHANGE_BONUS,
+  CROWD_REACTION_CHANCE, MAYBE_SHOW_HUMAN_CHANCE, CREATOR_VOICE_LINE_CHANCE,
+  HYPERDETAIL_BASE_CHANCE, HYPERDETAIL_INTENSITY_SCALE,
+} from './config'
 
 interface RoundDeps {
   HOME_A: number
@@ -691,7 +700,7 @@ async function playRound(event: RoundEvent) {
   const roundBonus = Math.min(2, Math.floor(event.round / 2))
   const exchangeCount = 3 + roundBonus + Math.floor(Math.random() * 3) + (intensity > 0.5 ? 1 : 0)
   // Hyperdetail scales with intensity
-  const hyperDetail = Math.random() < (0.05 + intensity * 0.45)
+  const hyperDetail = Math.random() < (HYPERDETAIL_BASE_CHANCE + intensity * HYPERDETAIL_INTENSITY_SCALE)
   const savedScaleAX = fA?.scale.x
   const savedScaleAY = fA?.scale.y
   const savedScaleBX = fB?.scale.x
@@ -702,7 +711,7 @@ async function playRound(event: RoundEvent) {
   let didChallengeVoice = false
   if (Math.random() < (creatorInFight ? 0.5 : 0.3)) {
     // Creator fights get existential commentary more often
-    if (creatorInFight && Math.random() < 0.6) {
+    if (creatorInFight && Math.random() < CREATOR_VOICE_LINE_CHANCE) {
       announceCreatorRound(); didChallengeVoice = true
     } else {
       const challengeVoice: Record<string, () => void> = {
@@ -883,7 +892,7 @@ async function playRound(event: RoundEvent) {
       attackerSide = Math.random() < Math.max(0.1, 0.4 - intensity * 0.25) ? loserSide : winnerSide
       exchangeCritical = false
       // Occasionally play a comedy sound on non-decisive hits
-      if (Math.random() < 0.15) { Math.random() < 0.5 ? sfxRandomComedy() : sfxRandomSilly() }
+      if (Math.random() < COMEDY_SFX_CHANCE) { Math.random() < 0.5 ? sfxRandomComedy() : sfxRandomSilly() }
     } else {
       // Draw: alternate
       attackerSide = ex % 2 === 0 ? 'a' : 'b'
@@ -898,8 +907,8 @@ async function playRound(event: RoundEvent) {
     const isCreatorFighter = attackerArch === 'the_creator'
     // Creator: always morph on ultimates, 70% on devastating crits
     const shouldMorph = isCreatorFighter
-      ? (isUltimate || (exchangeCritical && intensity > 0.6 && Math.random() < 0.7))
+      ? (isUltimate || (exchangeCritical && intensity > CREATOR_MORPH_INTENSITY_THRESHOLD && Math.random() < CREATOR_MORPH_CRIT_CHANCE))
-      : (isUltimate || (exchangeCritical && intensity > 0.7 && Math.random() < 0.4))
+      : (isUltimate || (exchangeCritical && intensity > BOT_MORPH_INTENSITY_THRESHOLD && Math.random() < BOT_MORPH_CRIT_CHANCE))
     let morphRevert: (() => Promise<void>) | null = null
     if (shouldMorph) {
       const attacker = k.get(attackerSide === 'a' ? 'fighterA' : 'fighterB')[0] as Fighter
@@ -985,7 +994,7 @@ async function playRound(event: RoundEvent) {
     }
 
     // Random scanline glitch during exchanges (25%)
-    if (Math.random() < 0.25) scanlineGlitch(0.2)
+    if (Math.random() < SCANLINE_GLITCH_CHANCE) scanlineGlitch(0.2)
 
     // Play the exchange — mix of choreography, brawls, clinches for ~50% physical contact
     if (!aWon && !bWon && isLastExchange) {
@@ -994,7 +1003,7 @@ async function playRound(event: RoundEvent) {
     } else {
       // Decide exchange type: choreography, brawl, or clinch
       // Brawl/clinch chance increases with later exchanges and higher intensity
-      const physicalChance = 0.35 + intensity * 0.2 + (ex > 1 ? 0.15 : 0)
+      const physicalChance = PHYSICAL_CONTACT_BASE + intensity * PHYSICAL_CONTACT_INTENSITY_SCALE + (ex > 1 ? PHYSICAL_CONTACT_EXCHANGE_BONUS : 0)
       const exchangeType = Math.random()
 
       if (!isLastExchange && exchangeType < physicalChance * 0.5) {
@@ -1003,17 +1012,17 @@ async function playRound(event: RoundEvent) {
       } else if (!isLastExchange && exchangeType < physicalChance) {
         // CLINCH COMBO: attacker grapples defender at close range
         await _clinchCombo(attackerSide, intensity)
-      } else if (!isLastExchange && Math.random() < 0.12) {
+      } else if (!isLastExchange && Math.random() < DODGE_CHANCE) {
-        // DODGE: defender dodges (reduced from 15% to 12% — more contact, fewer misses)
         await playDodge(attackerSide === 'a' ? 'b' : 'a')
         sfxDodge()
-        if (Math.random() < 0.4) sfxRandomFail(); else sfxBoing()
+        if (Math.random() < 0.4) sfxRandomFail()
+        else sfxBoing()
       } else {
         // CHOREOGRAPHY: signature move from the pool
         await playAttack(attackerSide, choreo, exchangeCritical)
 
         // COUNTER-ATTACK: defender fights back after getting hit (25% chance on non-final exchanges)
-        if (!isLastExchange && !exchangeCritical && Math.random() < 0.25) {
+        if (!isLastExchange && !exchangeCritical && Math.random() < COUNTER_ATTACK_CHANCE) {
           await k.wait(0.08)
           await _counterAttack(attackerSide === 'a' ? 'b' : 'a')
         }
@@ -1070,7 +1079,7 @@ async function playRound(event: RoundEvent) {
   // === THE CREATOR CAMEO ===
   // 6% chance per round (only if neither fighter IS the creator)
   const neitherIsCreator = botA.archetype !== 'the_creator' && botB.archetype !== 'the_creator'
-  if (neitherIsCreator && Math.random() < 0.06) {
+  if (neitherIsCreator && Math.random() < CREATOR_CAMEO_CHANCE) {
     const cameoX = k.width() / 2
     const cameoY = GROUND_Y - 80
     // Golden portal flash
@@ -1195,7 +1204,7 @@ async function playRound(event: RoundEvent) {
     announceCrowdReaction('cheer')
   } else if (aWon || bWon) {
     // Regular round win: crowd reacts (40%) — only SFX, no speech
-    if (Math.random() < 0.4) announceCrowdReaction(Math.random() < 0.5 ? 'cheer' : 'applause')
+    if (Math.random() < CROWD_REACTION_CHANCE) announceCrowdReaction(Math.random() < 0.5 ? 'cheer' : 'applause')
     // Heartfelt announcer moment (10% chance on normal, non-critical rounds)
     if (Math.random() < 0.1) {
       await k.wait(0.3)

server/src/engine/fight-loop.ts

@@ -1,3 +1,4 @@
+import { FIGHT_LOOP_INTERVAL_MS, ELO_MATCHING_RANDOMNESS } from '../lib/constants.js'
 import { db, schema } from '../db/index.js'
 import { runMockFight } from './mock.js'
 import { eq } from 'drizzle-orm'
@@ -31,7 +32,7 @@ export interface FightLoopOptions {
 
 export async function startFightLoop(options: FightLoopOptions = {}): Promise<void> {
   const {
-    intervalMs = 8000,
+    intervalMs = FIGHT_LOOP_INTERVAL_MS,
     maxFights = Infinity,
     matchmakingStyle = 'mixed',
     onFightStart,
@@ -161,8 +162,8 @@ function pickMatchup(
     const bot = pick(bots)
     const others = bots.filter(b => b.id !== bot.id)
     others.sort((a, b) => {
-      const diffA = Math.abs(a.eloRating - bot.eloRating) + Math.random() * 150
+      const diffA = Math.abs(a.eloRating - bot.eloRating) + Math.random() * ELO_MATCHING_RANDOMNESS
-      const diffB = Math.abs(b.eloRating - bot.eloRating) + Math.random() * 150
+      const diffB = Math.abs(b.eloRating - bot.eloRating) + Math.random() * ELO_MATCHING_RANDOMNESS
       return diffA - diffB
     })
     return [bot, others[0]]

server/src/engine/mock.ts

@@ -1,3 +1,4 @@
+import { STARTING_HP } from '../lib/constants.js'
 import { nanoid } from 'nanoid'
 import { logger } from '../lib/logger.js'
 import { createHash, randomBytes } from 'crypto'
@@ -433,8 +434,8 @@ export async function runMockFight(botAId: string, botBId: string): Promise<stri
     createdAt: now,
   })
 
-  let hpA = 200
+  let hpA = STARTING_HP
-  let hpB = 200
+  let hpB = STARTING_HP
   let comboA = 0
   let comboB = 0
   let winnerId: string | null = null

server/src/engine/orchestrator.ts

@@ -35,9 +35,7 @@ interface WebhookResponse {
   error: boolean
 }
 
-const MAX_ROUNDS = 10
+import { MAX_ROUNDS, KO_THRESHOLD, MAX_RESPONSE_BYTES, STARTING_HP, ELO_K_FACTOR, ELO_K_FACTOR_MOCK } from '../lib/constants.js'
-const KO_THRESHOLD = 0
-const MAX_RESPONSE_BYTES = 10 * 1024 // 10KB
 
 // Track bots currently in a fight to prevent concurrent fights
 const activeFighters = new Set<string>()
@@ -333,8 +331,8 @@ async function trackWebhookResult(botId: string, webhookUrl: string, succeeded:
 }
 
 async function executeFightRounds(fightId: string, botA: BotRecord, botB: BotRecord, arena: Arena, mode: 'free' | 'ranked' = 'free'): Promise<void> {
-  let hpA = 200
+  let hpA = STARTING_HP
-  let hpB = 200
+  let hpB = STARTING_HP
   let comboA = 0
   let comboB = 0
   let winnerId: string | null = null
@@ -447,13 +445,13 @@ async function executeFightRounds(fightId: string, botA: BotRecord, botB: BotRec
 
   const winnerName = winnerId === botA.id ? botA.name : winnerId === botB.id ? botB.name : 'nobody'
   const isPerfect = winnerId && (
-    (winnerId === botA.id && hpA === 200) ||
+    (winnerId === botA.id && hpA === STARTING_HP) ||
-    (winnerId === botB.id && hpB === 200)
+    (winnerId === botB.id && hpB === STARTING_HP)
   )
 
   // Finalize fight + update bot stats atomically
   const isMockFight = isMockBot(botA.webhookUrl) || isMockBot(botB.webhookUrl) || isClassicBot(botA.webhookUrl) || isClassicBot(botB.webhookUrl)
-  const kFactor = isMockFight ? 12 : 32 // Dampened Elo for mock/classic fights
+  const kFactor = isMockFight ? ELO_K_FACTOR_MOCK : ELO_K_FACTOR
   let winnerEloChange = 0
   let loserEloChange = 0
   let newWinnerEloFinal = 0

server/src/engine/scoring.ts

@@ -1,3 +1,4 @@
+import { ELO_DIVISOR, TIER_THRESHOLDS } from '../lib/constants.js'
 import type { Challenge } from './challenges.js'
 import { pick } from '../lib/utils.js'
 import { checkAnswer } from './answers.js'
@@ -523,7 +524,7 @@ export function calculateElo(
   loserElo: number,
   k: number = 32,
 ): { newWinnerElo: number; newLoserElo: number } {
-  const expectedWinner = 1 / (1 + Math.pow(10, (loserElo - winnerElo) / 400))
+  const expectedWinner = 1 / (1 + Math.pow(10, (loserElo - winnerElo) / ELO_DIVISOR))
   const expectedLoser = 1 - expectedWinner
 
   return {
@@ -534,12 +535,9 @@ export function calculateElo(
 
 // Tier calculation
 export function calculateTier(elo: number, wins: number): number {
-  if (elo >= 1900 && wins >= 40) return 6  // Legend
+  for (const t of TIER_THRESHOLDS) {
-  if (elo >= 1700 && wins >= 25) return 5  // Diamond
+    if (elo >= t.elo && wins >= t.wins) return t.tier
-  if (elo >= 1500 && wins >= 15) return 4  // Platinum
+  }
-  if (elo >= 1350 && wins >= 7) return 3   // Gold
-  if (elo >= 1200 && wins >= 3) return 2   // Silver
-  if (wins >= 1) return 1                   // Bronze
   return 0  // Baby
 }
 

server/src/lib/constants.ts

@@ -0,0 +1,33 @@
+// ═══════════════════════════════════════════════════════════════
+// Server constants — all tunable magic numbers in one place
+// ═══════════════════════════════════════════════════════════════
+
+// --- Fight rules ---
+export const MAX_ROUNDS = 10
+export const KO_THRESHOLD = 0
+export const STARTING_HP = 200
+export const MAX_RESPONSE_BYTES = 10 * 1024 // 10KB
+export const MAX_ANSWER_LENGTH = 2000
+export const MAX_TRASH_TALK_LENGTH = 200
+
+// --- Elo ---
+export const ELO_K_FACTOR = 32           // K-factor for real fights
+export const ELO_K_FACTOR_MOCK = 12      // Dampened K-factor for mock/classic fights
+export const ELO_DIVISOR = 400           // Standard Elo divisor
+
+// --- Tier thresholds ---
+export const TIER_THRESHOLDS = [
+  { tier: 6, elo: 1900, wins: 40 },  // Legend
+  { tier: 5, elo: 1700, wins: 25 },  // Diamond
+  { tier: 4, elo: 1500, wins: 15 },  // Platinum
+  { tier: 3, elo: 1350, wins: 7 },   // Gold
+  { tier: 2, elo: 1200, wins: 3 },   // Silver
+  { tier: 1, elo: 0,    wins: 1 },   // Bronze
+] as const
+
+// --- Default challenge timeout ---
+export const DEFAULT_CHALLENGE_TIMEOUT_MS = 8000
+
+// --- Fight loop ---
+export const FIGHT_LOOP_INTERVAL_MS = 8000
+export const ELO_MATCHING_RANDOMNESS = 150