Enter the drop chance, number of attempts, and optionally a luck boost to calculate the probability of not receiving a drop (dry streak) in Old School RuneScape (OSRS).

Dry Streak Calculation Formula

The following formula is used to calculate the probability of a dry streak in OSRS:

Dry Probability = (1 - 1 / Drop Chance) ^ Number of Attempts * 100

Variables:

  • Dry Probability is the chance of not receiving a drop after a given number of attempts (%)
  • Drop Chance is the probability of getting the drop in one attempt (1 in X)
  • Number of Attempts is how many times you have attempted to get the drop

To calculate the dry probability, raise the term (1 – 1 / Drop Chance) to the power of the Number of Attempts and multiply by 100 to get the percentage.

What is Dry Streak Calculation?

Dry streak calculation refers to the process of determining the probability of not receiving a rare drop in OSRS after a certain number of attempts. Understanding dry streak probabilities can help players manage their expectations and strategies when hunting for rare items. This calculator can be particularly useful for players aiming to complete boss drops or other rare item collections.

How to Calculate Dry Probability?

The following steps outline how to calculate the dry probability using the given formula.

  1. First, determine the drop chance of the item you are attempting to receive.
  2. Next, count the number of attempts you have made to get the drop.
  3. If applicable, include any luck boost percentage you have.
  4. Use the formula from above: Dry Probability = (1 – 1 / Drop Chance) ^ Number of Attempts * 100.
  5. Finally, calculate the dry probability by plugging in the values.
  6. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem:

Use the following variables as an example problem to test your knowledge.

Drop Chance = 1 in 200

Number of Attempts = 500

Luck Boost = 10%

FAQ

1. What is a dry streak?

A dry streak in OSRS refers to a series of attempts to receive a drop without success. It often occurs when players are trying to obtain rare items.

2. How is dry probability calculated?

Dry probability is calculated by raising the term (1 – 1 / Drop Chance) to the power of the Number of Attempts and multiplying by 100 to get the percentage.

3. How does luck boost affect drop chance?

Luck boost reduces the effective drop chance, increasing the probability of receiving a drop. It is factored into the dry probability calculation by modifying the drop chance.

4. Can this calculator be used for different activities in OSRS?

Yes, the dry streak calculator can be used for any activity in OSRS where a drop chance is known, such as boss drops, clue scrolls, and other rare item collections.

5. Is the calculator accurate?

The calculator provides an estimate of your dry streak probability based on the inputs provided. For exact figures, it’s best to refer to in-game statistics and data.