In many gacha systems each pull has a fixed base chance (p) of yielding a rare item. Players often perform a multiβpull, which groups several pulls together and may apply a small bonus that increases the odds on each successive pull.
The bonus is typically expressed as an incremental increase (b) per extra pull after the first. This means the first pull uses the base probability p, the second uses pβ―+β―b, the third pβ―+β―2b, and so on, up to the total number of pulls (n) in the bundle.
To compare the effectiveness of a multiβpull with bonus against a single pull, we calculate the probability of obtaining at least one rare item. This is done by finding the complement of the probability of missing the rare item on every pull and then subtracting from one.
How does the bonus work in a multi-pull?
What is the formula for calculating the odds in a multi-pull?
Can I use this calculator for any gacha game?
How does increasing the number of pulls affect my odds?
What if there’s no bonus in the gacha system?
Can this calculator help me decide how many pulls to do?
Is there a limit to the number of pulls I can calculate?
Results are for informational purposes only and do not constitute professional advice.
