**Tuning** How to Tune =========== 1. Playtest * Observe, tweak, repeat 2. Equations 1. Chance to hit, expected damage per time or per turn, expected rounds to death 2. D&D 1. Randomize by rolling dice (4, 6, 8, or 20-sided) 1. Expected average = (1 + sides) / 2 * Average for 1 6-sided die (1d6) is 3.5 1. Average from multiple rolls add * Average for 2 6-sided dice (2d6) is 7 1. Chance to hit from a 20-sided die (1d20) 1. Probability = weapon bonus + attacher bonus - armor bonus - defender bonus 2. Special case for 1 (miss) or 20 (critical hit: guaranteed hit, chance for bonus damage) 2. Damage done 1. Die + weapon bonus + player bonus 2. Critical hit: roll again for chance for 2nd damage roll 3. Damage per turn = * 0.05 * 0 * + 0.90 * (hitProb * avgDamage + (1-hitProb) * 0) * + 0.05 * (critProb * 2 * avgDamage + (1-critProb) * avgDamage) 4. Using to tune: target rounds to battle, adjust hit points or bonuses to hit target. 3. Spreadsheet 1. Interrelationship between health and weapon stats 1. Damage per turn or survivability 1. Expected player level & modifiers 1. Weapon availability 1. Monster stats 1. Tune to near 0 2. [Power progression (especially for RPG)](http://www.gamasutra.com/view/news/129714/The_craft_of_game_systems_Tuning_RPG_content.php) 3. [RTS production](http://www.somasim.com/blog/2015/04/how-to-tune-a-simulation-game/) 1. Graph from source to sink 2. Build typical cities 3. Tune to near 0 4. Metrics 1. Log events (death, progress, ...) 2. Graph (Examples from Forza, Paragon) 3. [Build heat map](http://www.gamasutra.com/view/feature/6155/hot_failure_tuning_gameplay_with_.php) What to Tune ============ 1. Power & Stamina 1. Player damage, hit probabilities 2. Enemy damage, hit probabilities 3. Player / Enemy health 4. Danger of ripple effect (see spreadsheet tuning) 2. Time limit 1. Racing 2. For expertise / challenge (e.g. Portal end-game) 3. Map design 1. Cover / safe zones (permanent or able to be destroyed) 2. Visibility of player or enemies 3. Enemy placement 4. AI Aggression 1. Sensitivity to alert 2. Chance to attack 5. Enemy count * Avoids ripple effect of stat changes 6. Resources (things you can run out of) 1. FPS: Ammo, Health; RTS: Ore, Food 2. Availability (e.g. pick-up placement before/after battle) 3. Production - more with time (FPS: healing; RTS: factories, farms) 4. Use - how long does it last (FPS: rate of fire; RTS: Consumption rate) 7. Checkpoints 1. Anytime or at set points 2. How much to replay? 1. Too close to battle & no restore could lock player into low health/low ammo losing situation 2. Too close to battle & full restore could make dieing too beneficial 3. Further back allows recovery & normalization of resources to designed levels, but frustrating replay. 8. Giving an advantage 1. Player assist 1. Aiming 2. Map & info on map (enemy / resource locations?) 3. HUD (flash showing direction) 4. Sound 5. Input precision / Hit precision * [e.g. Extra ledge](http://www.gamasutra.com/blogs/AdamSaltsman/20100929/88155/Tuning_Canabalt.php) 2. Enemy assist 1. Boost or reduce to match player level 1. Know where player is even when not in line of sight Other Resources =============== 1. [General](http://www.gamasutra.com/view/feature/3787/difficulty_is_difficult_designing_.php) 2. [Input, response, context](http://www.gamasutra.com/view/feature/130734/game_feel_the_secret_ingredient.php)