The next attempt does not remember
If each attempt has a 1% success chance and attempts are independent, the next attempt stays at 1% after every miss. Feeling that a win is “due” does not change the model. A pity rule is different: it explicitly changes the probability or guarantees a result after misses.
Calculate the chance of at least one
It is easier to count the opposite event: getting nothing. At success rate p, the failure chance is 1 − p. Missing n times has probability (1 − p)n. Subtract this from one to get the chance of at least one success.
For a hypothetical 1% rate, 100 tries give 1 − 0.99100 ≈ 63.40%. The remaining 36.60% is the chance of getting nothing. “One success per 100 tries on average” and “a success within 100 tries” are different statements.
Choose the right model
Use fixed-rate odds for independent pulls. Use the raffle calculator for draws without replacement, where the pool changes. Use a custom pity model only when the rules actually change after misses. A guarantee within a box does not establish independence between packs.
Put the idea to work
Pull odds · Raffle odds · Custom pity · Tries for a target chance