Luck calculator

Slime RNG luck calculator

Pick your hunt, active boosts, and game stage in three taps. Get your total luck, effective odds, AFK forecast, and the single highest-leverage upgrade to push next.

Player mode

Pick your session

Tap what matches your game.

1. What are you hunting?
2. What is active right now?
3. Where are you in the game?
▶ Advanced settings

How the formula works

The calculator multiplies every active luck source together to produce Total Luck:

total_luck = base × rebirth × luck_boost × zone × server × index × (1 + permanent% / 100)
effective_odds = base_odds ÷ total_luck
rolls_per_hour = 3600 ÷ cooldown_seconds
hit_chance(t) = 1 − (1 − 1 / effective_odds)rolls_per_hour × t

Rebirth multiplier uses 1.82^level — verified at tier 17 (in-game ×26,370 vs formula 26,425, 0.2% match). Auto Roll cooldown defaults to 0.94s, the in-game value with max Roll Speed upgrade. See the luck breakdown for the additive vs multiplicative split shown in-game.

FAQ

How does the Slime RNG luck calculator work?

Pick your session in three steps, or open Advanced settings to enter exact multipliers. The calculator multiplies every active luck source (rebirth, boosts, zone, server, index, permanent percent) into a Total Luck value, divides your target slime's base odds by that, and uses 1 − (1 − p)^rolls for the time-to-hit forecast.

Why does the rebirth multiplier use 1.82^level?

In-game footage on a level-17 rebirth shows the displayed multiplier at 26,370× (frame_0237 of our gameplay capture). 1.82^17 = 26,425, matching to within 0.2%. Full table on the /rebirth page.

What's the default 0.94s cooldown?

That's the Auto Roll cooldown shown in-game with a max-level Roll Speed upgrade. Without Roll Speed it's ~3s. Late-game stage preset uses 0.94s; New uses 3s.

What does "Best move" recommend?

It looks at your current setup and flags the single highest-leverage upgrade: Roll Speed if your cooldown is high, Luck Boost if no boost is active, Server Luck if everything else is maxed. The priority is roll throughput before luck multipliers — more rolls per hour multiplies whatever luck you do have.

Why does my actual hit time differ from the estimate?

RNG variance over 1,000 rolls can swing the hit time ±50% from the average. The 24-hour hit chance shows the probability of getting at least one drop within the window, not a guarantee.