Grand Blue (Roblox) Reroll Planner
Your odds of a Mythic race from bulk rerolls, and Trait Reroll stacking strategy.
The 0.15% Mythic race rate is creator-verified; the formula is exact math. Trait odds are not yet published, so bulk-roll your 0 Trait Rerolls from codes (FruitBasket, NewYouNewCrew) without expecting a fixed percentage. Always confirm live results in-game.
The math behind the planner
Each race reroll is an independent draw, so the chance of seeing at least one Mythic across n rolls follows the standard formula 1 − (1 − 0.0015)^n. At a 0.15% per-roll rate that means a single roll is 0.15%, 100 rolls is about 13.98%, and 1,000 rolls is roughly 77.7%. The curve is steep at first and then flattens — the first hundred rerolls buy you the most ground.
The planner does this arithmetic for you so you can see whether a stack is actually large enough to be worth spending, instead of rolling the moment you earn a reroll.
Race and Trait are two separate layers
Grand Blue rerolls live in two pools. Race rerolls change your character's race, where Human is the default and Mythic is the rarest outcome. Trait rerolls feed two slots — Trait 1 (primary) and Trait 2 (secondary) — which stack with each other rather than replacing one another.
Because the pools and their rerolls are separate, working on one never costs you progress on the other. Only the race pool has a published odds figure, so the planner shows an exact percentage for races and a running count for traits.
Why bulk rolling is the whole strategy
Rerolls come from codes, not from gameplay grinding, so the supply arrives in bursts. A single code event can hand you a double-digit stack of rerolls. Spending them one at a time as they arrive means you sample the low-probability tail rarely; banking them and rolling a large batch is what actually gives you a realistic shot at a Mythic.
- Bank rerolls from several code drops before you start rolling.
- Roll the pool with the larger stack first — bigger n means better odds.
- Re-enter your new count after each batch so the odds figure stays honest.
Where to get rerolls
- Race Rerolls — e.g. HappySunday grants 20 Race Rerolls.
- Trait Rerolls — e.g. FruitBasket and NewYouNewCrew grant Trait Rerolls.
- Check the codes page before rolling; a fresh drop can change your odds materially.
Frequently Asked Questions
What are the real Mythic race odds?
The Mythic race sits at roughly 0.15% per roll (creator-verified). The planner applies the exact formula 1 − (1 − 0.0015)^n, so 100 race rerolls give about a 13.98% chance of at least one Mythic.
Do Trait rerolls use the same odds?
Trait rarity odds are not yet published. The planner tracks your Trait Reroll count for bulk-rolling strategy, but does not show a fixed percentage — stack code grants (FruitBasket, NewYouNewCrew) and confirm traits in-game.
Where do rerolls come from?
Codes. HappySunday grants 20 Race Rerolls; FruitBasket and NewYouNewCrew grant Trait Rerolls. Save several drops and roll in bulk rather than one at a time.
Should I reroll race or traits first?
They are separate pools with separate rerolls, so the order does not compete for resources. A common plan is to bank both types from code events and roll whichever pool has the larger stack, since bulk rolling is what moves your odds.
Does rolling one at a time beat rolling in bulk?
No — the math is identical per roll, but bulk rolling is simply the accumulation of many independent rolls. Because each roll is independent, ten single rolls and one batch of ten carry the exact same probability; bulk is only a convenience, not a luck trick.