To roll Ninja with 90% confidence in 8 hours AFK, the leanest free stack is R6 + Ultra Luck + 2× Gamepass + Lucky + Huge Lucky, finishing in roughly ~4.9 hrs. Want it faster? Add potions or a gamepass; the table below ranks tradeoffs.
| Window | Stack (fastest path) | Time to 90% | Reachable? |
|---|---|---|---|
| 1 h | Baseline only | — | No |
| 4 h | R7 + Ultra Luck + 2× Gamepass + Lucky + Huge Lucky | ~2.7 hrs | Yes |
| 8 h | R6 + Ultra Luck + 2× Gamepass + Lucky + Huge Lucky | ~4.9 hrs | Yes |
| 24 h | R4 + Ultra Luck + 2× Gamepass + Lucky + Huge Lucky | ~16.3 hrs | Yes |
Ninja has a base drop rate of 1 in 1.3M per roll. To reach 90% confidence of pulling at least one within an 8-hour AFK window, you need to land at effective odds where the geometric distribution `1 - (1 - p)^n` clears 0.9 over the available roll count.
The plan above uses a luck multiplier of roughly ×6429.8, pulling effective odds to 1 in 196. Across 7.5 rolls/min for 8 hours, that clears 90%.
The other two rankings (cheapest, simplest) trade time for resource savings. If you’re grinding overnight, the cheapest plan often beats the fastest one because the extra hours cost nothing.
Ninja earns a retained stack page because it is the prismatic target with the clearest combat payoff. Players searching for it usually need a real plan, not a generic calculator output.
Ninja fits late-game accounts that have outgrown divine attackers and can afford longer potion or rebirth-backed windows. It is too rare for casual early rolling but not as unreachable as Huge targets.
Ninja math uses documented prismatic odds and the planner confidence formula. The exact time estimate still depends on the roll-speed assumption, so the page should present it as planning guidance.
Ninja differs from King because King is partly prestige and support, while Ninja is direct burst damage. That makes Ninja the better preset for players asking which prismatic target improves clears.
The common mistake with Ninja is using a short one-hour window and expecting stable results. The odds need either a dense stack or more AFK time, so the 4h and 8h rows matter.
Cost columns are concrete. Time columns assume our reconciled defaults (Lucky Slime Passive ×3, potion duration 3 min, 5 rolls/min standard or 7.5 with Roll Speed Boost). These values are sourced from three independent community references but haven’t been primary-verified in-game. Treat as guidance, not gospel.