# Brimstone key

The brimstone key is a key obtained from killing monsters while on a Slayer task given by Konar quo Maten. It is used to open the brimstone chest. The average value of a drop from the brimstone chest is 98,044.89. Upon death in the Wilderness, a brimstone key converts to two coins for the killer.

The probability of receiving a key as a drop increases with the slain monster's Combat level. For monsters with combat level 100 or higher, the probability is between ${\displaystyle 1/100}$ and ${\displaystyle 1/50}$, scaling linearly and capping at level 350. Specifically, the probability for a monster with combat level ${\displaystyle L}$ is[1]

${\displaystyle {\frac {1}{120-\left\lfloor L/5\right\rfloor }}}$.

For monsters with combat level ${\displaystyle L}$ smaller than level 100, the probability follows the curve[2]

${\displaystyle {\frac {1}{100+\left\lfloor (L-100)^{2}/5\right\rfloor }}}$.

Additionally, if the monster has a Slayer level requirement, there is a 20% boost in the drop probability.[3]

## Item sources

For an exhaustive list of all known sources for this item, see here (include RDT).
SourceLevelQuantityRarity
Aberrant spectre96 11/82
Abhorrent spectre253 11/55
Abyssal Sire350 11/40
Abyssal demon124 11/76
Ahrim the Blighted98 11/100
Alchemical Hydra426 11/40
Ancient Wyvern210 11/62
Ancient Zygomite109 11/78
Ankou (m)75–98 11/225
Aviansie69–148 11/292
Baby black dragon83 11/157
Baby blue dragon48 11/640
Baby red dragon48 11/640
Basilisk Knight204 11/63
Basilisk Sentinel358 11/40
Basilisk61 11/323
Berry71 11/268
Black demon Level 178172; 178; 184 11/85
Black demon Level 172172; 178; 184 11/85
Black demon Level 184172; 178; 184 11/85
Black dragon Level 227227 11/74
Bloodveld76; 81 11/172
Blue dragon111 11/97
Brine rat70 11/224
Bronze dragon131; 143 11/93
Brutal black dragon318 11/56
Brutal blue dragon271 11/65
Brutal red dragon289 11/62
Callisto470 11/50
Cave kraken127 11/75
Cerberus318 11/56
Chaos Elemental305 11/59
Chaos Fanatic202 11/79
Choke devil264 11/53
Colossal Hydra309 11/46
Commander Zilyana596 11/50
Crazy archaeologist204 11/79
Dagannoth (Waterbirth Island) Level 9090 11/120
Dagannoth (Waterbirth Island) Level 8888 11/128
Dagannoth Prime303 11/59
Dagannoth Rex303 11/59
Dagannoth Supreme303 11/59
Dagannoth fledgeling70 11/280
Dagannoth spawn42 11/772
Dagannoth74; 92 11/235
Dark beast182 11/66
Deviant spectre169 11/68
Dharok the Wretched115 11/97
Drake192 11/64
Dust devil93; 110 11/87
Fire giant86; 104; 109 11/139
Flight Kilisa159 11/88
Gargoyle111 11/77
General Graardor624 11/50
Giant Mole230 11/74
Greater Nechryael200 11/64
Greater abyssal demon342 11/40
Greater demon (m)92–113 11/112
Grotesque Guardians 11/43
Guardian Drake386 11/40
Guthan the Infested115 11/97
Hellhound122; 127; 136 11/95
Hydra194 11/64
Insatiable Bloodveld202 11/63
Insatiable mutated Bloodveld278 11/51
Iron dragon189; 215 11/82
Jelly78 11/156
K'ril Tsutsaroth650 11/50
Kalphite Guardian141 11/91
Kalphite Queen333 11/53
Kalphite Soldier85 11/145
Kalphite Worker28 11/1,136
Karil the Tainted98 11/100
King Black Dragon276 11/64
Kraka91 11/116
Kraken291 11/48
Kree'arra580 11/50
Lizardman brute73 11/245
Lizardman shaman150 11/90
Lizardman53; 62 11/541
Lizardman53; 62 11/388
Long-tailed Wyvern152 11/71
Marble gargoyle349 11/40
Mithril dragon304 11/59
Monstrous basilisk135 11/74
Mountain troll69; 71 11/292
Mutated Bloodveld123 11/76
Nechryael115 11/77
Nechryarch Normal 11/48
Night beast374 11/40
Nuclear smoke devil280 11/51
Pee Hat91 11/116
Red dragon152 11/89
Repugnant spectre335 11/42
Rock (Troll)111 11/97
Rune dragon380 11/50
Sarachnis318 11/56
Scorpia225 11/75
Screaming twisted banshee144 11/72
Skeletal Wyvern140 11/73
Skotizo321 11/55
Smoke devil160 11/70
Spiked Turoth244 11/56
Spitting Wyvern139 11/73
Steel dragon246; 274 11/70
Stick104 11/99
Taloned Wyvern147 11/72
Thermonuclear smoke devil301 11/47
Thrower Troll67 11/317
Torag the Corrupted115 11/97
Troll general113 11/97
Turoth83; 85; 87; 89 11/125
Twig71 11/268
Twisted Banshee89 11/99
Venenatis464 11/50
Verac the Defiled115 11/97
Vet'ion454 11/50
Vitreous Jelly206 11/62
Vitreous warped Jelly241 11/56
Vorkath392; 732 11/50
Vyrewatch Sentinel151 11/89
Vyrewatch87–125 11/133
Warped Jelly112 11/77
Waterfiend115 11/97
Wingman Skree143 11/91
Wyrm99 11/80
Zulrah725 11/50
Zygomite74; 86 11/188
Zygomite74; 86 11/111

## Changes

Date Changes
28 May 2020
(update)

A bug causing the Brimstone key drop rate to be lower than intended for monsters with a combat level of 100 or higher was fixed.[4]

## Trivia

• The symbol on the key is that of Yin and yang ("阴阳"/"陰陽"), which, in Chinese philosophy, are the two "primal" elements which create, shape, and influence everything in existence and have to be kept in balance. This references the philosophy of the Kahlith and their masters, the Tasakaal, which is to maintain the balance between life and death.

## References

1. Jagex. Mod Kieren's Twitter account. 16 January 2019. (Archived from the original on 26 May 2020.) Mod Kieren: "It follows a curve up until level 100 then scales linearly between those 2 values upto level 350 combat. Creatures over thsi[sic] will cap at 1/50. [1]"
2. Jagex. Mod Kieren's Twitter account. 16 January 2019. (Archived from the original on 29 April 2020.) Mod Kieren: "0.2*(CBLEVEL - 100)^2 + 100"
3. Jagex. Mod Ash's Twitter account. 8 June 2020. (Archived from the original on 11 June 2020.)
4. Jagex. Mod Ash's Twitter account. 6 June 2020. (Archived from the original on 8 June 2020.) Mod Ash: "Actually Mod Maylea & I had this fixed in the update before last - sorry it didn't make the newspost at the time."