OSRS ToA Calculator
Estimate Tombs of Amascut unique chance from raid level, reward points and deaths.
Estimate ToA unique chance from points
32,000 eligible reward points · 3,700 points per 1%
OSRS Wiki ToA reward-point formula · reviewed 2026-09-05. The group rolls only one unique; an individual’s allocation is proportional to contribution. Room scoring, MVP bonuses, path details, disconnects, and restricted-item 1/50 rerolls are outside these three inputs.
What the OSRS ToA Calculator calculates
The OSRS ToA Calculator estimates the party chance of seeing one Tombs of Amascut unique from raid level and hidden reward points. It implements the current piecewise scaled-raid-level equation and displays the 55 percent cap.
Reward points begin with 5,000, but those starting points are removed for loot and purple percentage. Each entered death deducts 20 percent of current points with a minimum deduction of 1,000 before that final subtraction.
Use the ToA Calculator
- 1
Enter invocation raid level and total reward points before the final start-point subtraction.
- 2
Add deaths in their actual sequence count.
- 3
Read party chance, then use personal contribution only to discuss who receives a rolled unique.
A result you can audit
Each section documents the calculation and the limits that apply to this specific gameplay problem.
How This OSRS ToA Calculator Works01+
Scaled RL equals raid level through 310; from 310–430 it is 310 + (level−310)÷3; above 430 it is 350 + (level−430)÷6. One percentage point requires 10,500 − 20×scaled RL eligible points.
Chance percent is eligible points divided by points-per-percent, capped at 55. Only one unique can be rolled, and an individual’s allocation is proportional to their contribution.
Worked Example for the OSRS ToA Calculator02+
At raid level 400, scaled RL is 340 and one percent requires 3,700 points. With 37,000 eligible points after deductions, the party chance is exactly 10 percent; this Wiki example is covered by a unit test.
How to Use the OSRS ToA Calculator Result03+
Use the estimate to compare invocation and survival scenarios, not to predict a particular item. Unique weighting changes with raid level, and restricted-item rerolls are separate from the initial purple chance.
OSRS ToA Calculator Accuracy and Limitations04+
The tool does not calculate room damage, MVP awards, path points, team contribution shares, common loot, pet chance, restricted-item 1/50 rerolls, or item weighting. Hidden points entered incorrectly produce a correspondingly wrong estimate.
ToA unique-chance stages
The order of point deductions and raid scaling matters.
| Stage | Rule | Cap |
|---|---|---|
| Death | −20%, minimum 1,000 | At zero |
| Starting points | Subtract 5,000 at loot | Not negative |
| Scaled RL | Piecewise after 310 | Formula |
| Unique chance | Points ÷ points-per-1% | 55% |
Official references used for this page
OSRS calculator FAQs
Clear answers about calculations, data, independence, privacy and practical use.
How does OSRS ToA raid level change unique chance?
Raid level is transformed by the piecewise scaled-RL formula, reducing reward points needed for each percentage point.
Why does the OSRS ToA tool subtract 5,000 points?
Players start with 5,000 reward points, but the current loot calculation removes them when determining loot and purple percentage.
What is the maximum OSRS ToA unique chance?
The party chance for one unique is capped at 55 percent; excess points do not create a second roll.
Does OSRS ToA party chance equal personal chance?
The party first rolls one unique; if successful, player allocation is proportional to individual contribution.