Loot Drop Calculator 🎲

Understanding Drop Rates and Probability

In most games, when an item has a 1% drop rate, it means you have a 1 in 100 chance of getting it every single time you complete the activity. This is known as independent probability. Getting unlucky on your 99th attempt does not increase your chances on the 100th attempt. The base drop rate remains 1%.

Cumulative Probability (Why 1% x 100 ≠ 100%)

A common misconception in gaming is that if you do an activity with a 1% drop rate 100 times, you are guaranteed the drop. This is mathematically incorrect. Instead, we use cumulative probability to figure out the chances of getting the item at least once over multiple attempts.

• To find this, we actually calculate the chance of you getting absolutely nothing.
• If a drop rate is 1%, the chance of failing is 99%.
• Failing 100 times in a row is calculated as: 0.99 ^ 100 = 0.366 (or 36.6%)
• Therefore, your chance of getting the drop at least once in 100 attempts is 63.4%.

What is Bad Luck Protection (Pity System)?

Because pure RNG (Random Number Generation) can lead to extremely frustrating streaks of bad luck, many modern games implement "pity systems." These systems artificially increase your chances the longer you go without a drop, or simply guarantee the item after a set number of attempts (e.g., getting a guaranteed legendary character on your 90th pull in Genshin Impact). Use the toggle in the calculator to see how pity systems completely change the math.