This tool calculates the probability of a successful stealth kill in video games, tabletop RPGs, and competitive gaming scenarios. It factors in player stats, enemy awareness, and environmental modifiers to give accurate odds. Use it to optimize your build, plan encounters, or balance game mechanics.
How to Use This Tool
Select your game type from the dropdown menu to contextualize the calculation. Enter your player character's stealth stat and the enemy's perception stat, both as values between 0 and 100. Choose the enemy's current awareness level, available environmental cover, and engagement distance from the provided dropdowns. Add any active buffs or debuffs to the modifier field if applicable, then click Calculate Probability to see your results. Use the Reset button to clear all inputs and start over.
Formula and Logic
The calculator uses a multi-step formula to determine stealth kill probability:
- Base Probability: Clamp(Player Stealth Stat - Enemy Perception Stat, 0, 100)
- Apply awareness penalty multiplier: 1 - (Awareness Penalty % / 100)
- Apply cover bonus multiplier: 1 + (Cover Bonus % / 100)
- Apply distance multiplier: 1 + (Distance Bonus % / 100)
- Add active modifiers, then clamp the final result between 0 and 100
All multipliers are applied sequentially to the base probability before flat modifiers are added. Critical failure and success chances are derived from the final adjusted probability.
Practical Notes
Stealth calculations vary widely across gaming contexts. In video games, stealth stats are often hidden or scaled non-linearly, so use observed in-game values for best accuracy. Tabletop RPGs may use dice roll systems where this probability represents the chance to beat a static difficulty check. Competitive games frequently receive balance patches that adjust stealth, perception, or cover values, so always check the latest patch notes before calculating. RNG (random number generation) means actual in-game results may vary from calculated probabilities, especially over small sample sizes. For tabletop games, game master (GM) discretion may override calculated values with flat modifiers.
Why This Tool Is Useful
Gamers can use this tool to optimize character builds, plan stealth routes, and avoid unnecessary combat encounters. Game designers can balance stealth mechanics by testing probability ranges for different player and enemy stat combinations. Streamers and content creators can use the tool to explain odds to viewers in real time. Competitive players can min-max stealth strategies to gain an edge in tournaments or ranked matches.
Frequently Asked Questions
What if my game uses tiered stats instead of numbers?
Convert tiered stats to approximate 0-100 values: S-tier = 90, A-tier = 75, B-tier = 60, C-tier = 40, D-tier = 20. Adjust based on the game's specific scaling if known.
How do I account for lighting or sound modifiers?
Add lighting or sound penalties/bonuses to the Active Modifiers field. For example, a dark environment might add +10 to the modifier, while loud footsteps might add -15.
Does this work for games with random crit systems?
Yes, the Critical Success Chance field represents the additional chance of a guaranteed kill when your final probability exceeds 80%. Check your game's specific crit rules to adjust this threshold if needed.
Additional Guidance
Always use tested in-game values rather than theoretical max stats for the most accurate results. Environmental factors like rain, fog, or NPC patrol patterns may add additional modifiers not included in the default calculation—add these to the Active Modifier field. For tabletop games, cross-reference results with your game's core rulebook to ensure compliance with official mechanics. Remember that calculated probabilities are theoretical, and short-term RNG variance can cause streaks of successes or failures unrelated to the calculated odds.