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Your assignment odds
Point-unlock tasks
Possible tasks
| Monster | Chance | Weight | Amount | Slayer | |
|---|---|---|---|---|---|
| Metal Dragons | 5.7% | 14 | 35-45(ext 150-200) | - | |
| Abyssal Demons | 4.9% | 12 | 130-200(ext 200-250) | 85 | |
| Dark Beasts | 4.5% | 11 | 10-20(ext 110-135) | 90 | |
| Araxytes | 4.1% | 10 | 60-80(ext 200-250) | 92 | |
| Hellhounds | 4.1% | 10 | 130-200 | - | |
| Black Dragons | 3.7% | 9 | 10-20(ext 40-60) | - | |
| Cave Kraken | 3.7% | 9 | 100-120(ext 150-200) | 87 | |
| Dagannoth | 3.7% | 9 | 130-200 | - | |
| Greater Demons | 3.7% | 9 | 130-200(ext 200-250) | - | |
| Kalphite | 3.7% | 9 | 130-200 | - | |
| Nechryael | 3.7% | 9 | 130-200(ext 200-250) | 80 | |
| Smoke Devils | 3.7% | 9 | 130-200 | 93 | |
| Black Demons | 3.3% | 8 | 130-200(ext 200-250) | - | |
| Bloodveld | 3.3% | 8 | 130-200(ext 200-250) | 50 | |
| Drakes | 3.3% | 8 | 50-110 | 84 | |
| Gargoyles | 3.3% | 8 | 130-200(ext 200-250) | 75 | |
| Suqahs | 3.3% | 8 | 60-90(ext 186-250) | - | |
| Wyrms | 3.3% | 8 | 100-160(ext 200-250) | 62 | |
| Aberrant Spectres | 2.9% | 7 | 130-200(ext 200-250) | 60 | |
| Fire Giants | 2.9% | 7 | 130-200 | - | |
| Fossil Island Wyverns | 2.9% | 7 | 20-50(ext 55-75) | 66 | |
| Skeletal Wyverns | 2.9% | 7 | 20-40(ext 50-70) | 72 | |
| Spiritual Creatures | 2.9% | 7 | 130-200(ext 181-250) | 63 | |
| Trolls | 2.5% | 6 | 130-200 | - | |
| Ankou | 2.0% | 5 | 50-80(ext 91-150) | - | |
| Dust Devils | 2.0% | 5 | 130-200(ext 200-250) | 65 | |
| Frost Dragons | 2.0% | 5 | 70-120(ext 180-240) | - | |
| Blue Dragons | 1.6% | 4 | 110-170 | - | |
| Cave Horrors | 1.6% | 4 | 130-200(ext 200-250) | 58 | |
| Elves | 1.6% | 4 | 110-170 | - | |
| Kurask | 1.6% | 4 | 130-200 | 70 | |
| Mutated Zygomites | 0.8% | 2 | 20-30 | 57 | |
| Waterfiends | 0.8% | 2 | 130-200 | - |
Game data on this page comes from the Old School RuneScape Wiki, used under CC BY-NC-SA 3.0.
OSRS Slayer task optimizer
See the real probability of every Slayer task from each of the nine Slayer masters, Mortimer included. Enter your combat and Slayer levels and the tool shows each task's chance - its assignment weight divided by the total weight of your eligible pool - and how blocking tasks or unlocking point tasks shifts your odds.
Frequently asked questions
How are Slayer task odds calculated?
Each task a master can give has an assignment weight. Your chance of a specific task is its weight divided by the summed weight of every task you're eligible for at your combat and Slayer level.
How many tasks can I block?
Up to 6 with the standard unlocks (5 base blocks plus the expansion). Blocking removes a task from your pool, which raises the odds of every remaining task.
What are point-unlock tasks?
Tasks you buy with Slayer reward points to add them to a master's assignment list, such as boss tasks. They only appear once unlocked, so enabling one increases your pool.