RNG Roll Odds Calculator: Chance Across Repeated Rolls

What are your chances over repeated rolls?

One in N chanceNumber of rolls

Example inputs only — not verified game stats. Calculations stay in your browser.

Calculate

Enter your values, then choose Calculate.

What do the inputs mean?

One in N means a probability of 1 divided by N on each attempt. Use the effective probability for the specific result, not a guessed number from an unrelated game. Rolls is the number of attempts in the session you want to model. A previous unsuccessful session is not added as a guarantee that the next attempt must succeed.

This is a general probability tool for players of Defeat Anime RNG and other RNG games. It contains no extracted game data. The default numbers are examples, not a particular unit’s confirmed odds.

How is the result calculated?

For constant success probability p and n independent attempts, the chance of at least one success is 1 − (1 − p)^n. The expected number of successes is n × p. Expected count is an average over repeated hypothetical sessions, not an inventory promise for your next session.

For example, hypothetical odds of one in 100 over 100 independent rolls give about 63.4%, not 100%, for at least one success. At the same odds, 69 rolls reach at least 50% and 299 reach at least 95%. There is still a chance of getting no successes at either threshold.

When should you not use this model?

Situation	Why the simple calculation may not apply
A guaranteed reward after a set count	Attempts are no longer described only by constant independent odds
Odds change during a session	A single p does not describe every attempt
A limited pool is depleted	Outcomes may depend on earlier draws
A luck effect is undocumented	Guessing its multiplier invents an input

When a game explicitly publishes different probabilities for each attempt, the no-success probabilities must be multiplied individually instead. This calculator does not infer that sequence.

Is the result a spending recommendation?

No. Choose a time or resource limit independently of the estimate. A long unlucky streak does not make the next independent attempt more likely. Use our shard planning guide to separate a budget from a hoped-for outcome.

Method and privacy

The formula is shown above and implemented locally in your browser. No account connection is used, and the tool does not send your inputs to a server. Numerical edge cases, invalid input and the worked example are checked in the project’s automated tests.