Beta
OSRS DPS Calculator, Boss Fight Simulator & Gear Optimizer
Find your best-in-slot equipment, work out DPS, max hit and time-to-kill against any boss, then simulate the whole kill tick by tick. Free, private, and it runs entirely in your browser.
100% free · No account · Nothing to install · Runs entirely in your browser
Watch a real Maggot King kill, tick by tick
A full Monte Carlo simulation of the actual fight, not just a DPS number.
Pick Maggot King and the simulator plays out its real rotation thousands of times: the ranged and magic phases, the screech gaps, and the low-HP melee enrage. It works out which weapon belongs in your hands during each phase (here a Harmonised nightmare staff for the ranged and magic windows and a Scythe of vitur for the melee enrage), fires your special attacks when they beat your auto-attack, models the melee step-under punish, and folds in thralls and burn damage. The result is the spread of kill times you would actually see in game, from fastest to slowest, along with the average, median and kills per hour. Every simulated kill can be replayed tick by tick.
Drag the chart to replay any simulated kill tick by tick.
Every tool in one place
Click any card to jump straight into that tool.
DPS Calculator
DPS, max hit, hit chance, time-to-kill and kills/hour against any boss, with prayer, potion, spell and special-attack support.
Open the calculator →
Boss Fight Simulator
Full Monte Carlo kills against real phases, punish windows, specials and per-phase gear swaps, with the true spread of kill times.
Simulate a kill →
Best Setup by Boss
Ready-made best-in-slot melee, ranged and magic loadouts for popular bosses. Open any of them straight into the calculator.
Browse best setups →
Drop Simulator
Roll kills one at a time or in batches, green-log a whole boss, or simulate straight to the pet or item you're hunting.
Simulate drops →
Import your gear
Load your combat stats from your RSN and import your bank or collection log, so Find Best only picks gear you actually own.
Import & optimize →Find your best-in-slot in one click
Plug in your account, pick a boss, let Find Best build the optimal loadout.
- Every style, every slot. Find Best searches melee, ranged and magic and returns the top weapons per style, each with its own optimal support gear.
- Set bonuses included. It seeds full sets (Void, Blood Moon, Barrows, Inquisitor's, crystal) as whole units, so a set only wins when its bonus actually beats the alternatives.
- Optimize around locked gear. Lock the pieces you want to keep and Optimize this Equipment fills the rest for maximum DPS.
- Only what you own. Import your bank or collection log and the search is limited to gear you actually have.
- Share it. Every build travels as a single link. Hand it to a friend and it opens exactly as you left it.
Gear a whole raid at once
One equipment list, scored against every boss in the run.
Group Encounters takes one equipment list and scores it against every boss in a whole raid or wave event (Chambers of Xeric, Theatre of Blood, Tombs of Amascut, the Inferno or the Colosseum) side by side. Instead of optimizing one boss at a time, you can see which loadout carries the entire run and where a gear swap is worth it.
Simulate boss drops
See how lucky or dry you'd really get.
Pick any boss and roll kills one at a time or in batches. Green-log the whole boss to see how long a full collection log takes, or simulate straight to the single item or pet you're hunting and find out how dry you could realistically go. Full raids (CoX, ToB and ToA) are included.
Theorycraft unreleased items
See how strong proposed gear is before it's even in the game.
RuneBuddy includes proposed and unreleased items straight from Jagex's dev blogs, like the Fractured Archive's TzHaar-Ket Breaker and Ascension crossbows, with their full mechanics. They're always selectable, and a single toggle lets Find Best use them, so you can plan exactly how they'll perform on release day.
Why RuneBuddy?
No account, no install, and nothing sent to a server.
Frequently asked questions
- Is RuneBuddy free?
- Yes. RuneBuddy is completely free, with no account and nothing to install. The whole site runs in your browser.
- Can I simulate a full boss kill, not just DPS?
- Yes. The Boss Fight Simulator runs thousands of complete kills against a boss's real phases, screech gaps, step-under punishes, enrage and special attacks. On Maggot King it swaps between your ranged, magic and melee gear per phase and shows the full spread of kill times, including average, fastest, slowest and kills per hour.
- Do I need an account or to install anything?
- No. There's no sign-up and nothing to download. Open the calculator and start. Your settings are saved locally in your browser.
- Can I optimize using only items I own?
- Yes. Import your bank or collection log and Find Best will only pick from gear you actually own.
- Does Find Best consider set bonuses like Void or Blood Moon?
- Yes. It seeds full sets (Void, Barrows, the Moons sets, Inquisitor's, crystal) as whole units, so it can find a set bonus a piece-by-piece search would miss, and it only picks a set when the bonus gives the highest DPS.
- What is Group Encounters?
- It scores one equipment list against every boss in a whole raid or wave event (CoX, ToB, ToA, the Inferno or the Colosseum) side by side, so you can pick the best loadout for the entire run at once.
- Does RuneBuddy include unreleased items?
- Yes. Proposed and unreleased items from Jagex's dev blogs are included with their full mechanics. They are always selectable, and an opt-in toggle lets Find Best use them.
- Where do the stats come from?
- Every item and monster stat is sourced from the Old School RuneScape Wiki, so the combat math matches in-game numbers.
- Does it work on mobile?
- Yes. The calculator, optimizer, fight simulator and drop simulator all work on mobile browsers.