Mortimer OSRS Guide: Slayer Master Tasks, Mortifiers & Block List
Quick Decision Snapshot
Mortimer is OSRS' new Slayer Master on Wyrmscraig. Unlock him at 100 Combat and 70 Slayer, choose between 2-3 tasks, and learn the Mortifier unlocks, 100-point skip costs, and how his two-slot block list works.
- Mortimer is OSRS' new Slayer Master on Wyrmscraig
- Unlock him at 100 Combat and 70 Slayer, choose between 2-3 tasks, and learn the Mortifier unlocks, 100-point skip costs, and how his two-slot block list works.
Mortimer is Old School's newest Slayer Master, added with Wyrmscraig on 29 July 2026. He is built around player choice: instead of a single assignment, he offers a pick between two tasks, with powerful Mortifier bonuses unlocking as you complete work for him.
He is a different beast to every other master — his tasks cost more to skip, he only has two block slots, and he pays no Slayer Points unless you unlock the Points Mortifier. Here's everything you need to know before switching.
How to Unlock Mortimer
Mortimer is found in the caverns on Wyrmscraig during the Fallen From Grace quest.
| Requirement | Level |
|---|---|
| Combat | 100 |
| Slayer | 70 |
OR 99 Slayer, regardless of Combat level.
You'll also need 62 Sailing to reach the island and 60 Crafting to start the quest. See our Wyrmscraig guide for full quest requirements.
How His Tasks Work
- Task choices: Mortimer offers a choice between two assignments instead of one. Complete tasks to unlock a third choice after 50 tasks.
- Superior-only task list: every creature on his task list has a Superior variant, making this the best master in the game for farming Superior Slayer drops.
- Expensive skips: skipping costs 100 Slayer Points — double most other masters.
- No Turael reset: you cannot reset your task through Turael, so a bad roll sticks unless you skip or complete it.
- Only two block slots: each costs 120 Slayer Points (up from the usual five slots).
- No Slayer Points: he doesn't award points unless you have the Points Mortifier active.
The 100-Point Skip vs the Two-Slot Block
Because blocks are limited to two, most players run one long-term block (their worst task) and use the other slot reactively. Skipping at 100 points is expensive, but with the Points Mortifier active every task pays points again — so the skip cost becomes self-funding once you unlock it.
Mortifiers — Unlock Schedule
Mortifiers are powerful bonuses that occasionally appear alongside your task choices, offering extra rewards or benefits depending on the assignment you pick. The unlock schedule was halved from the original proposal after community feedback:
| Mortifier | Tasks Completed | Effect |
|---|---|---|
| Points Mortifier | 0 | You earn Slayer Points for Mortimer tasks |
| Quantity Mortifier | 0 | Improved task quantities |
| Clue Mortifier | 15 | More clue scrolls from tasks |
| Superior unique drop Mortifier | 25 | Better Superior unique drop odds |
| XP Mortifier | 40 | More Slayer XP per task |
| Triple task selection | 50 | Choose between three tasks |
The early unlocks (Points and Quantity at 0 tasks) mean you never lose out by switching to Mortimer — you're earning points and bigger tasks from your very first assignment.
Partner Slayer with Mortimer
Your task choices are determined independently of your partner's unlocks — a partner cannot reduce or alter your task pool. If you select a task your partner doesn't meet the Slayer level or quest requirements for, you still receive the assignment as normal, and your partner cannot be assigned your task if they have a task choice pending.
What to Block at Mortimer (Fastest XP)
Mortimer only gives you two block slots at 120 Slayer Points each (vs 100 at other masters for five slots), so your block list is your most valuable resource. The goal for fastest Slayer XP is to block high-weight, low-Superior-value tasks and keep those with strong Superior uniques or burst potential.
| Task to block | Why block it at Mortimer | What to keep instead |
|---|---|---|
| Dust devils | High weight off-task, weak Superior value unless bursting (see Bursting & Barraging guide) | Nechryaels in smoke dungeon (better burst XP) |
| Nechryaels | Often blocked at other masters; Superior Mortifier doesn't rescue their GP/hr | Abyssal demons & Smoke devils (higher Superior table) |
| Spiritual creatures | Forced Zammy GWD trips, slow Superior rate | Dust devils if bursting, otherwise GWD bosses |
| Hellhounds | Low Slayer XP and weak Superior drop vs weight | Gargoyles / Nechryaels (if bursting) |
| Warped terrorbirds / Cave horrors | Low weight but long trips for little XP | Compare task weights with Slayer Task Calculator |
| Any task you hate skipping at 100 points | Skips cost 100 Slayer Points (double) — blocking is cheaper long-term than skipping | Keep your current block + rotate the second slot reactively |
Default starter block list for Mortimer (cost: 240 points): Dust devils + Nechryaels if you don't burst, or Spiritual creatures + Hellhounds if you do. Use the second slot reactively for a week — if you find yourself paying 100 points to skip the same task twice, burn the 120 to block it instead. The Slayer guide has master-by-master weight comparisons to fine-tune.
Is Mortimer Worth Switching To?
Switch to Mortimer if you:
- Want the best Superior farming in the game (his entire task list has Superior variants)
- Are 100 Combat / 70 Slayer or higher and want a more engaging Slayer loop
- Want to grind Mortimer-exclusive content without losing Slayer Points (Points Mortifier unlocks immediately)
Stay with another master if you:
- Rely on Turael skipping or a wide block list — Mortimer's two-slot limit and 100-point skips are punishing for block-list players
- Prefer AFK tasks like Cannoning — his superior-heavy list is more active
- Are still building Slayer points — though the Points Mortifier largely cancels this concern
Plan your Slayer route with our Slayer Task Calculator and compare master options in the Slayer guide.
FAQ — What is the best block list for Mortimer OSRS?
What is the best block list for Mortimer OSRS? With only two slots, block your most-skipped 100-point task first (usually Dust devils or Spiritual creatures), then one generic low-value task like Nechryaels. Keep burst-able tasks if you burst — otherwise block them.
How much does Mortimer's block list cost? 120 Slayer Points per slot (240 for two), and skips are 100 points each — blocking saves points after two skips of the same task.
What to block at Mortimer for Superior farming? Keep every task with a Superior variant you want to farm (Abyssals, Smoke devils, Gargoyles) and block the highest-weight task you never want Superior drops from.
Related Tools & Guides
- Wyrmscraig Guide — Fallen From Grace quest, Mad Angel boss, and island content
- Slayer Task Calculator — Plan task weights and block lists
- Slayer Guide — Compare Slayer masters and training routes
- Combat Calculator — Verify you meet the 100 Combat requirement
- Drop Rate Calculator — Estimate Superior unique drop odds with the Mortifier
Ready to apply what you learned?
Plug your stats into our free OSRS calculators to see exact XP, GP costs, and time estimates before you commit to a training method.
Darren started playing the original RuneScape 2 back in the day and came back when Old School RuneScape launched. He's played on and off over the years and built OSRSToolkit to give players a single place to find reliable tools, calculators, and guides — all informed by real in-game experience.