1. XP Progression Curve Models
| Model | Formula | Growth Behavior | Typical Use Case | Design Notes |
|---|
| Linear | XP = Base × Level | Constant increase | Casual / short games | Predictable pacing |
| Exponential | XP = Base × Rate^Level | Rapid late growth | RPGs / live service | Controls late-game lifespan |
| Quadratic | XP = Multiplier × Level² | Smooth scaling | Most modern RPGs | Balanced grind curve |
| Logarithmic | XP = Base × log(Level+1) | Fast early, slow later | Skill systems | Reduces early friction |
| Hybrid | XP = Level² × Mult + Base | Controlled scaling | Long progression | Most flexible |
Typical exponential rates:
| Rate | Perceived Pace |
|---|
| 1.05 | Very gradual |
| 1.1 | Smooth |
| 1.15 | Noticeable grind |
| 1.2 | Hardcore |
2. Damage Calculation Models
| Model | Formula | Scaling Stability | Common Genres | Notes |
|---|
| Flat Reduction | Damage = ATK − DEF | Poor late scaling | Classic RPG | Can cause zero damage problems |
| Percent Reduction | Damage = ATK × (100 / (100 + DEF)) | Very stable | Action RPG / MMO | Industry standard |
| Multiplicative | ATK × Mods × Buffs × Crit | Complex scaling | ARPG / Strategy | Requires careful tuning |
| Armor Curve | Damage = ATK × (1 − Armor%) | Predictable | Shooters | Easy readability |
3. Time-to-Kill Benchmarks
| Genre | Target TTK | Combat Feel |
|---|
| Tactical FPS | 0.2 — 0.8 sec | High lethality |
| Arena Shooter | 1 — 3 sec | Reactive |
| Action RPG | 5 — 20 sec | Ability driven |
| MOBA | 3 — 12 sec | Tactical bursts |
| MMO | 20 — 60 sec | Rotation based |
| Survival | 2 — 10 sec | Tension focused |
4. Health Regeneration Models
| Model | Formula | Typical Range | Player Perception |
|---|
| Flat Regen | HP/sec = Fixed | 1–10 HP/sec | Simple |
| Percent Regen | Max HP × Rate | 0.5–2% | Scales with progression |
| Delayed Regen | After delay | 3–7 sec delay | Modern standard |
| Combat Regen | Reduced in combat | 25–50% normal | Tactical pacing |
5. Loot Drop Rate Benchmarks
| Tier | Probability | Player Expectation |
|---|
| Common | 40 — 70% | Frequent |
| Uncommon | 20 — 40% | Regular |
| Rare | 5 — 15% | Exciting |
| Epic | 1 — 5% | Memorable |
| Legendary | 0.1 — 1% | Event level |
Pseudo-random adjustment range: +0.5% to +2% per failure
6. Critical Hit Standards
| Parameter | Typical Range | Impact Level |
|---|
| Crit Chance | 5 — 25% | Baseline |
| High Crit Builds | 30 — 60% | Volatile |
| Crit Multiplier | 1.25x — 2x | Standard |
| Burst Multiplier | 2.5x — 3x | High variance |
Expected damage formula:
Damage = Base × (1 + CritChance × CritMultiplier)
7. Economy Flow Ratios
| Metric | Healthy Range | Risk if Exceeded |
|---|
| Income vs Spending | 1 : 0.9 | Inflation |
| Sink Coverage | 80 — 95% | Currency hoarding |
| Reward Velocity | Stable | Player burnout |
| Inflation Growth | <5% per week | Economic collapse |
8. Cooldown Design Ranges
| Ability Type | Typical Cooldown | Design Intent |
|---|
| Core ability | 3 — 8 sec | Rotation |
| Utility | 10 — 30 sec | Tactical choice |
| Ultimate | 60 — 180 sec | Power spike |
| Charge regen | 10 — 30 sec | Flexibility |
Cooldown reduction formula:
CD = Base × (1 − Reduction%)
9. Reward Timing Cadence
| Reward Scale | Interval | Purpose |
|---|
| Micro reward | 30 — 90 sec | Engagement loop |
| Small reward | 5 — 15 min | Retention |
| Medium reward | 30 — 60 min | Session satisfaction |
| Major reward | 2 — 6 hrs | Long goals |
10. Power Growth Multipliers
| Game Scope | Total Power Increase |
|---|
| Short campaign | 2x — 5x |
| Mid length | 10x — 50x |
| RPG | 100x — 1000x |
| MMO / live service | 10,000x+ |
11. Difficulty Scaling Models
| Model | Behavior | Best Use |
|---|
| Static | Fixed difficulty | Competitive |
| Level scaling | Matches player | Open world |
| Soft scaling | Partial adjustment | Hybrid RPG |
| Dynamic (DDA) | Performance based | Casual accessibility |
Common performance metrics: deaths, accuracy, completion time
12. Stat Allocation Benchmarks
| Stat Category | Allocation Range |
|---|
| Offense | 35 — 45% |
| Defense | 25 — 35% |
| Utility | 15 — 25% |
| Luck / variance | 5 — 10% |
13. RNG Influence Targets
| Genre | RNG Influence |
|---|
| Competitive | 5 — 15% |
| Action | 15 — 30% |
| RPG | 30 — 60% |
| Roguelike | 50 — 80% |
14. Risk vs Reward Scaling
Standard heuristic:
Reward ∝ Risk²
| Risk Level | Suggested Reward |
|---|
| Low | 1x |
| Moderate | 2–3x |
| High | 4–6x |
| Extreme | 8–10x |
15. Progression Milestone Targets
| Session Length | Expected Progress |
|---|
| 10 min | Minor upgrade |
| 30 min | Small milestone |
| 1 hr | Level gain |
| 3 hrs | Major unlock |
Quick Design Heuristics
| Principle | Guideline |
|---|
| Early progression speed | Fast first hour |
| Feedback loop timing | <60 sec |
| Economy health | Maintain sinks |
| RNG fairness | Use PRD |
| Player power curve | Smooth ramp |
| Complexity introduction | Gradual |
