TOA Drop Rate Calculator for OSRS

🏺 TOA Drop Rate Calculator

Estimate Tombs of Amascut purple chance from raid level, team points, personal deaths, selected unique weight, target raids, and completion pace.

Tip: A higher invocation is only better if your points and completion rate survive the extra mistakes. Compare deathless and death-heavy presets before committing.
📋TOA Raid Presets
⚙️Raid Drop Inputs
Calculator note: Points are treated as end-of-raid total points before the personal death adjustment below. Team purple chance is capped at 55%.
Raid levels above 400 scale slower, and levels above 550 do not add more unique modifier value.
Your name chance is based on your effective points divided by total team points.
Individual total points are capped at 64,000. Use your loot tracker estimate when available.
For solos this field is ignored. For teams, enter each teammate's average finished points.
Each death subtracts 20% of current total points, with at least 1,000 points removed.
Specific item odds use the 24-weight table and entry-mode restriction handling.
Cumulative chance shows the odds of seeing at least one selected result over this many completions.
Used for the expected hours and comparison grid, not for changing per-raid drop odds.
Shows how many completions are needed for that cumulative probability.
📊Current Raid Snapshot
Expert
Mode bracket
300
Effective modifier level
0.00%
Team purple chance
2.14
Raids per hour
Tombs of Amascut Drop Estimate
Personal purple chance
0.00%
Any tradeable purple in your name
Selected unique chance
0.00%
Per completed raid
Expected raids
0
Average completions per selected result
Cumulative chance
0.00%
Across 100 completions
🧮Comparison Grid
Personal Output
Effective points20,000
Point share100%
Death loss0
Team Roll
Total points20,000
Points per 1%4,500
Live weight24.00
Selected Hunt
Item weightAny
Confidence raids0
Expected hours0 hr
Dry Streak
No hit odds0.00%
Runs entered100
Estimate typeAverage
📚TOA Reference Tables
Raid level modifier breakpoints
Raid levelModeModifier ruleFarm note
0 to 149EntryFull valueRestricted uniques
150 to 299NormalFull valueFull table opens
300 to 399ExpertFull valueStrong purple jump
400 to 550Expert+One-third valueSlower scaling
551+CapNo added valueDifficulty only

The calculator treats 550 as the unique modifier cap and keeps accepting raid levels above it for planning context.

Unique table weights
UniqueWeightShareEntry handling
Osmumten's fang729.17%Open
Lightbearer729.17%Open
Elidinis' ward312.50%Restriction roll
Masori mask28.33%Restriction roll
Masori body28.33%Restriction roll
Masori chaps28.33%Restriction roll
Tumeken's shadow14.17%Restriction roll

For sub-150 raids, restricted uniques are modeled with a 1 in 50 bypass roll after the item is selected.

Point mechanics used
MechanicCalculator valueWhere usedEffect
Base unique10,500 ptsPoints per 1%Starting denominator
Raid level20 per levelModifierLowers denominator
Death20% or 1,000Your pointsReduces share
Player cap64,000 ptsInput clampLimits one player
Team cap55%Team purpleLimits total roll

Personal deaths are applied sequentially to your entered points; teammate points should already include their own deaths.

Preset comparison targets
PresetRaid levelTeamPoint style
150 Solo Baseline1501Learning farm
250 Trio Farm2503Even shares
300 Expert Solo3001Full table
400 Team Push4004High total
550 Modifier Cap5508Capped scaling

Use the preset buttons as starting points, then replace the points and minutes with your own completion data.

Tip: When comparing team sizes, keep the same player quality assumption. More team points improve the chest roll, but your name chance still follows your point share.
Tip: Expected raids are an average, not a promise. The dry-streak card is often the better sanity check for long Shadow or Masori hunts.

The math is simple: each death will cost 20 percent of your points. However, the penalty isn’t flat; it’s sequential, which means it compounds fast. You don’t need to open up Excel to know what this looks like. But if you want to know exactly how much your odds decrease after each death, you’ll need to calculate it correcty.

This mean that your team’s point distribution across members is simulated by the tool above. It will calculate exactly what percent of reward pool you control based on your personal contribution and the team’s effective raid level. Why does this matter? The unique drop chance isn’t simply a flat percent for everyone in group. Even if the group overall have a good chance to trigger a purple drop, your own unique drop chance is based off your portion of the points, which goes up with higher invocation levels.

Use Math to Improve Your Loot Odds

That’s why going from 300 to 500 gives you less value for your effort, as shown on page’s reference table (which details those weight changes). The “maximize modifier” obsession doesn’t account for how team coordination tend to be the real bottleneck, not any one person’s power level.

You can put yourself in a situation where everyone on your team get maxed out. But if you’re running with seven other people who take forever to get through things, it won’t matter what you do individually. Your small gain in drop probability will be overwhelmed by the sheer amount of time everyone puts in. Better to run with a few friends who know what they’re doing and wrap up fast every time, then to run with an entire team of eight who end up taking like forty-five minutes to try because nobody can communicate properly and/or has low enough combat stats.

Using the calculator, you can play around with different numbers and see when having more people actualy improves your chances individually or merely waters down the whole thing.

The other thing spreadsheets don’t record is the psychology of dry spells. You might have a 20% probability of getting something on a given raid run and yet not see anything after two hundred runs. Players break down over that sort of variance, switching modes too early or even blaming themselves for bad luck rather than acknowledging statistical reality. On average, you’ll get this much out of a raid. But that’s the mean; the mean lies if all you have is a single life in Old School RuneScape. A better way to think about your expectations is to think in terms of confidence intervals. How many raids do I need before I’m guaranteed to find it with a 90 percent probability?

The thing most players don’t realize about these items is that they has a weight to them. By default, they sit at the bottom of the probability hierarchy. They’re designed that way because chasing them means you need both points and patience, something that very few people want to spend in today’s game. Before you dump hundreds of hours into grinding for rare drops like Masori armor parts and Tumeken’s shadow, use the calculator to break down the odds of those items. This will give you an idea of just how steep your climb is before you start investing time into it. It cuts through the hype and leaves you with nothing but cold, hard probabilities.

At the end of the day, raiding is as much about performance as it is expectation management. You can plug in your real numbers, such as completion time and deaths. You are no longer guessing. You can compare solo runs against duo or trio setups to see where your time is best spent. Trio comparison. And that’s when the math stops caring about how difficult the last night was for you: It only cares about the points on the board right now.

Let that clear understanding direct your decision about whether you’ll go for the big wins with higher level runs, or settle into something more safe but less valuus each time out. More often than not, whether you have a good raid or waste your night has little to do with luck. It’s simply better math before you ever log in.

TOA Drop Rate Calculator for OSRS

Leave a Comment