Reaching 99 Slayer in Old School RuneScape (OSRS) is a long-term goal that requires patience and persistence. With 13,034,431 XP needed to achieve this milestone,players soon realize the critical role that the Block List plays in RuneScape gold making the journey smoother. If you're unfamiliar with the Block List,it's a feature that allows you to avoid certain monsters that you'd rather not fight during your Slayer tasks. After all,Slayer is not a skill you can actively grind; it's more of a byproduct of training your combat skills. As a result,efficiency and enjoyment are key to making this experience more bearable. And yes,I've completed 99 Slayer—it took years.

For most players,Slayer isn't about grinding for hours on end. It's something that naturally progresses as you train other combat skills. While some players focus exclusively on Slayer,most use it to supplement their training,so the tasks should ideally be enjoyable. To help with this,players can pay 100 Slayer reward points at a Slayer Master to block specific monsters that they find tedious or unenjoyable. However,blocking monsters is more than just about avoiding frustration—it also has the potential to improve your efficiency and experience gains.

This guide focuses on how to use the Block List to avoid low-XP or inefficient monsters. But it's important to note that enjoyment should always come first. If you're not enjoying the grind,you'll likely burn out quickly. So while maximizing XP is essential,don't forget to have fun with the journey.

At the beginning,you'll have five available slots on your Block List. After earning 300 quest points,you can unlock a sixth slot,and after completing the Lumbridge Elite Diary,a seventh slot will open up. By the time you hit this point,you should already be working toward obtaining the Quest Cape,as it's crucial for long-term progress in OSRS. The various diaries in the game also provide valuable rewards and experience,which makes them worth pursuing.

Now,let's dive into the monsters you should consider blocking for the best XP gains. For this guide,I'll assume you have all seven slots open and that you are using Duradel as your Slayer Master (or Kuradel if you've completed the "While Guthix Sleeps" quest). The following recommendations are in no particular order.
Hellhounds

Hellhounds are among the first monsters that should be considered for blocking. While these creatures are decent for AFK training and have some valuable drops like the Primordial Crystal,their XP gains are slow. Hellhounds are single-target monsters,meaning that they don't offer the multi-target opportunities that would help you maximize your XP. This can make grinding through a Hellhound task incredibly time-consuming.

On top of that,Hellhounds don't drop much in terms of valuable loot. You may occasionally get an Ensouled Head,clue scrolls,or a rare Smoldering Stone,but these don't offset the amount of time and effort spent fighting them. As a result,Hellhounds are an inefficient choice for a Slayer task and should be blocked early.
Cave Krakens

Cave Krakens are another monster that should be avoided. They have a high Slayer task weight,meaning you're likely to encounter them frequently. But despite the frequent assignments,Cave Krakens are slow to kill. Since you can only kill them with magic (preferably a Trident of the Swamp),these tasks tend to take longer than many other monsters. Additionally,their drop table is relatively poor,so you won't be earning much GP from these tasks.

The high task weight and lack of efficient XP gains make Cave Krakens prime candidates for the Block List. Blocking them will save you a lot of time in buy OSRS gold the long run,allowing you to focus on more rewarding tasks.