# BALANCE.md — Formulas & Starter Numbers

All numbers below go in `src/game/constants.js`. Tune there, not inline.

## Energy
```
ENERGY_MAX = 100
ENERGY_REGEN_SECONDS = 180      // +1 per 3 min
ENERGY_TONIC_RESTORE = 25
```
```
computeEnergy(stored, updatedAtMs, nowMs):
  if nowMs <= updatedAtMs: return {energy: stored, updatedAtMs}
  gained = floor((nowMs - updatedAtMs) / (REGEN_SECONDS*1000))
  if stored + gained >= MAX: return {energy: MAX, updatedAtMs: nowMs}
  return {energy: stored + gained, updatedAtMs: updatedAtMs + gained*REGEN_SECONDS*1000}
```
(Keep leftover partial interval by advancing the timestamp only by whole ticks.)

## Leveling
```
xpToNext(level) = floor(100 * level^1.5)        // L1→2: 100, L2→3: 282, L5→6: 1118, L10→11: 3162
MAX_LEVEL = 50
STAT_POINTS_PER_LEVEL = 3
```
On level-up: `hp_current = maxHp`, loop to handle multiple level-ups from one reward.

## Derived stats
```
maxHp        = 50 + vit*10 + level*5 + itemBonusVit*10
primary      = STR | INT | AGI   (by class)
attack       = 5 + primary*2 + level + equipment.bonus_attack
defense      = floor(vit*1.5) + equipment.bonus_defense (+10% if Warrior)
speed        = 10 + agi
critChance%  = min(40, 5 + floor(agi*0.5)) (+8 if Ranger)
critMult     = 1.5
```
Equipment `bonus_str/agi/int/vit` are added to the base stats BEFORE the derived formulas.

## Damage
```
mitigation   = 100 / (100 + defenderDefense)
raw          = attackerAttack * mitigation
variance     = rng.range(0.9, 1.1)
dmg          = max(1, round(raw * variance * (crit ? critMult : 1)))
```
Mage bonus: if defenderDefense >= 15, multiply `raw` by 1.15.
Monsters crit at a flat 5%.

## Rewards
```
xp   = monster.xp  * levelDiffMult
gold = rng.int(monster.gold_min, monster.gold_max) * levelDiffMult
levelDiffMult = clamp(1 + 0.1*(monster.level - hero.level), 0.2, 1.5)
```
Loot: for each row in `loot_table` for that monster, roll `rng.float()*100 < chance_pct`.
Max 2 distinct loot drops per fight.

## Defeat penalty
`goldLost = floor(gold * 0.10)`; `hp_current = 1`; `deaths += 1`.

## Rest
`restCost = level * 5` gold → heals to full. Free if hp already full is rejected (`NOTHING_TO_HEAL`).

## Starter monsters (use or tweak)
| Zone | Name | Lv | HP | Atk | Def | Spd | XP | Gold |
|---|---|---|---|---|---|---|---|---|
| Meadows | Giant Rat | 1 | 20 | 6 | 1 | 12 | 8 | 1–3 |
| Meadows | Meadow Wolf | 2 | 32 | 9 | 3 | 16 | 14 | 2–5 |
| Meadows | Goblin Scrapper | 3 | 45 | 12 | 5 | 11 | 22 | 4–9 |
| Forest | Webspinner | 5 | 70 | 18 | 8 | 15 | 40 | 8–16 |
| Forest | Bandit Cutthroat | 6 | 90 | 22 | 12 | 14 | 55 | 12–24 |
| Forest | Mossback Treant | 8 | 150 | 26 | 22 | 7 | 85 | 15–30 |
| Crags | Ember Imp | 10 | 130 | 34 | 15 | 20 | 120 | 25–45 |
| Crags | Stone Golem | 12 | 260 | 38 | 40 | 6 | 170 | 30–60 |
| Crags | Ashfang Drake | 14 | 300 | 50 | 30 | 18 | 260 | 50–100 |

## Starter items (≥ 20 required; this is a minimum seed list)
| Item | Type | Rarity | Lv | Buy | Bonus |
|---|---|---|---|---|---|
| Rusty Sword | weapon | common | 1 | 20 | +3 atk |
| Apprentice Staff | weapon | common | 1 | 20 | +2 int, +1 atk |
| Hunter's Shortbow | weapon | common | 1 | 20 | +2 agi, +1 atk |
| Iron Blade | weapon | uncommon | 5 | 120 | +8 atk, +2 str |
| Oakwood Staff | weapon | uncommon | 5 | 120 | +6 atk, +3 int |
| Yew Longbow | weapon | uncommon | 5 | 120 | +6 atk, +3 agi |
| Emberforged Greatsword | weapon | rare | 10 | 600 | +18 atk, +4 str |
| Leather Jerkin | armor | common | 1 | 25 | +3 def |
| Chainmail Vest | armor | uncommon | 5 | 140 | +9 def, +2 vit |
| Drake-scale Armor | armor | rare | 12 | 700 | +22 def, +4 vit |
| Wooden Charm | trinket | common | 1 | 30 | +1 vit |
| Wolf-fang Pendant | trinket | uncommon | 3 | 90 | +2 agi |
| Ember Ring | trinket | rare | 10 | 450 | +3 str,+3 int |
| Minor Healing Potion | consumable | common | 1 | 15 | effect heal:50 |
| Greater Healing Potion | consumable | uncommon | 8 | 60 | effect heal:150 |
| Energy Tonic | consumable | uncommon | 1 | 80 | effect energy:25 |
| Rat Tail | material | common | 1 | 0 | sell 2g |
| Wolf Pelt | material | common | 2 | 0 | sell 5g |
| Spider Silk | material | uncommon | 5 | 0 | sell 12g |
| Imp Horn | material | uncommon | 10 | 0 | sell 30g |
| Drake Scale | material | rare | 14 | 0 | sell 90g |

Materials with `buy_price = 0` sell at: common 2×level, uncommon 4×level, rare 8×level (round down, min 1).

## Starter loot chances
Common material from its zone's weakest monsters: 40%. Uncommon gear drops: 3–5%.
Rare gear drops: 0.5–1% from top-tier zone monsters. Healing potion: 8% anywhere.

## Expedition starters
| Name | Min Lv | Duration | Energy | XP | Gold |
|---|---|---|---|---|---|
| Scout the Old Road | 1 | 10 min | 10 | 40 | 10–25 |
| Raid the Bandit Camp | 5 | 1 h | 25 | 300 | 80–160 |
| Delve the Hollow | 10 | 4 h | 40 | 1400 | 300–600 |
(Use short durations such as 20–60 s via an env flag `DEV_FAST_TIMERS=1` for testing.)