OSRS Bonecrusher Passive Prayer: Elite Diary Slayer Guide

Game screenshots and facts are cited from the Old School RuneScape Wiki (strategy, equipment, drops, and related pages). Writing is original editorial, not a copy of the wiki article.

Why Passive Prayer Matters for Slayer

Slayer is already one of the most efficient skills for training combat, gathering drops, and making money. Prayer, on the other hand, is traditionally a bank-buying skill — you spend millions on bones or shards and stand at an altar for hours. The bonecrusher necklace changes that equation. With the elite Morytania Diary completed, every bone you would normally leave on the ground during a Slayer task becomes full Prayer XP automatically. No inventory clutter, no extra clicks, no lost kills per hour.

Passive training is the cheapest Prayer method in terms of active time, because you are already killing the monsters. It will never match the raw XP per hour of a gilded altar or libation bowl, but over the course of 99 Slayer it can add tens of millions of Prayer XP. This guide covers how to set it up, what rates to expect, and when to switch to active offering methods.

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Requirements: Unlocking Full Bonecrusher Value

Before you start crushing bones for full XP, you need two core unlocks. Missing either one cuts your passive Prayer XP in half or leaves you without the ability at all.

If you already have a bonecrusher but not the elite diary, you will still get half XP per bone. That is often not worth the inventory space or the ecto-token cost, so many players wait until the diary is done.

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How the Bonecrusher Necklace Works

The bonecrusher automatically crushes bones dropped by monsters you kill, as long as it is charged with ecto-tokens. Normally the bonecrusher grants half the Prayer XP you would get from burying the bone yourself. With the elite Morytania Diary, that becomes the full bury XP. For example, a dragon bone buried manually gives 72 Prayer XP. With the elite diary, the bonecrusher gives 72 XP per dragon bone automatically; without the diary, it gives 36.

The bonecrusher necklace combines the bonecrusher effect with the stats of a dragonbone necklace, if you prefer to wear it in the neck slot. The exact combat bonuses and how it compares to other neckwear are outside this research pack, so verify those numbers on the wiki before buying one.

Charges are consumed per bone crushed, so the token cost scales with the number of bone-dropping monsters you kill. For high-volume tasks like dust devils, nechryael, or dragons, the charge upkeep is trivial compared to the XP gained, but it is a recurring cost to factor in.

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Passive XP Rates: Bonecrusher vs Ash Sanctifier vs Ectoplasmator

Passive Prayer XP is not a fixed number — it depends on your kill rate, the bones or ashes dropped, and whether you have the relevant elite diary. The table below compares the main passive tools, along with the semi-passive option of reanimating ensouled heads.

Method	Attention	XP source	XP multiplier	Notes
Bonecrusher (no elite diary)	Fully passive	Bones dropped	50% of bury XP	Charged with ecto-tokens; half rate.
Bonecrusher (elite Morytania Diary)	Fully passive	Bones dropped	100% of bury XP	Recommended for serious passive training.
Ash sanctifier (no elite diary)	Fully passive	Ashes dropped	50% of scatter XP	Charged with death runes.
Ash sanctifier (elite Kourend & Kebos Diary)	Fully passive	Ashes dropped	100% of scatter XP	Pairs with bonecrusher on demon tasks.
Ectoplasmator	Fully passive	Spectral creatures	20% of max health	Requires 40 Prayer; stacks with bonecrusher on ankou.
Reanimating ensouled heads	Semi-active	Heads dropped on ground	Spell-dependent	Cast reanimation spells directly on heads; counts toward Slayer tasks (except reanimated dragons).

To estimate your own passive XP, use the formula: bones per hour × bury XP per bone (or half without elite). For example, if a Slayer task has you killing 150 dragons, that is 150 × 72 = 10,800 Prayer XP from bonecrusher alone with elite diary, and 5,400 without. That is not enough to replace active training, but it adds up across hundreds of tasks.

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Active Offering Methods Compared

When you need a burst of Prayer XP — for 77 Prayer to unlock Augury and Rigour, or 85 for Achievement Diary — passive bonecrushing will be too slow. Active methods are far more XP per hour but require dedicated time and often significant gp.

Method	XP rate (approx.)	Cost / Risk	Best for
Gilded altar (both burners lit)	350% per bone; high XP/hr	Requires POH, marrentill, and bones; no risk	Fast, afkable (relatively), reliable
Chaos Temple (Wilderness)	High; bones have 50% chance to not be consumed	Wilderness PK risk; can stack with Zealot's robes	Budget high XP with risk management
Libation bowl (blessed bone shards + wine)	~670k–1.42M XP/hr depending on prep and Prayer level	High prep time but very high XP; sunfire wine pushes top end	Late-game burst training
Cremating urium remains	35k–57k XP/hr	Profitable or break-even; needed for Zealot's robes	Obtaining Zealot's set early, not raw XP
Bonecrusher passive (elite diary)	Varies, often 5k–20k XP/hr depending on task	Zero active time; token cost	Zero-time XP during Slayer

If you are an ironman or want a safer active route, our OSRS HCIM Safe Prayer guide compares gilded altar and Chaos Temple in detail. For a deeper dive on Ectofuntus versus Chaos Altar efficiency, see OSRS Prayer: Ectofuntus vs Chaos Altar Guide.

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Building a Slayer Loadout for Passive Prayer

Once you have the elite diary and bonecrusher, the setup is simple. Carry the bonecrusher in your inventory (or wear the necklace variant), keep it charged, and go about your normal Slayer task. For tasks that drop ashes as well as bones — such as demons or certain spectral creatures — carry an ash sanctifier and ectoplasmator to stack multiple passive XP sources.

Prayer bonus gear is still valuable because you will be using overheads and offensive prayers. The passive XP does not change your prayer drain, but every prayer point saved is less time sipping potions and more time killing. High Prayer bonus items like the proselyte armour are common for melee tasks, but verify current gear rankings on the wiki before investing.

Reanimating ensouled heads is another layer you can add without banking. Carry the appropriate runes for the heads that drop, and cast the reanimation spell directly on the head before it disappears. Reanimated monsters still count toward your Slayer task (except reanimated dragons), so this doubles as extra combat XP and Prayer XP with a bit of extra attention.

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Common Mistakes and Hidden Costs

• Using bonecrusher without elite diary. Half XP is usually not worth the token cost, especially on tasks with valuable bones like dragon bones. Pick up and bank these if you are not elite.
• Forgetting to charge ecto-tokens. The bonecrusher silently stops working, and you lose all passive XP.
• Crushing bones you should sell. Some bones are expensive. If the gp value of a bone outweighs the Prayer XP to you, turn the bonecrusher off or pick them up. The elite diary makes this tradeoff better, but always check current GE prices.
• Ignoring ash sanctifier on demon tasks. Demons drop ashes that would otherwise be left on the ground. With the elite Kourend & Kebos Diary, the sanctifier is free Prayer XP on tasks you are already doing.
• Relying on passive for a specific level. If you need 77 Prayer soon, bonecrusher alone could take weeks. Use active methods for time-sensitive goals.
• Overpaying for active supplies without shopping around. Prices fluctuate. Use the Grand Exchange and wiki price graphs; buying gold from a marketplace can help you lock in a training session when prices dip.

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Time-to-Goal and Cost Tradeoffs

Let’s put numbers on a common goal: getting from 70 to 77 Prayer. The gap is roughly 500k–600k XP depending on exact level. With a gilded altar using dragon bones, that could be just a few hours of offering. With the libation bowl and prepped sunfire wines, it could be under an hour at high Prayer levels. With passive bonecrusher alone, you would need many Slayer tasks — potentially 20–50 hours of combat depending on the monsters.

That does not mean passive is bad. It means passive is a supplement. A player who does Slayer from 80 to 99 will kill tens of thousands of bone-dropping monsters. If half of those drop dragon bones or big bones, the total Prayer XP from bonecrusher could exceed 5–10 million. That is a huge amount of zero-time XP that would otherwise cost millions in supplies and hours at an altar.

For active methods, supply cost is the main barrier. Dragon bones, superior dragon bones, and blessed bone shards all cost gp. Here is where a gold purchase or a training boost becomes an honest shortcut if your real-life time is more valuable than your gp. You are not breaking the game; you are buying the resources to train more efficiently, exactly as you would buy any other supply.

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When Buying Gold or a Boost Is the Honest Shortcut

There is no shame in valuing your time. If you have limited hours to play, spending 10 hours grinding gp for bones to then spend 3 hours at an altar is worse than buying the bones directly and spending those 10 hours doing Slayer with a bonecrusher. That Slayer time also gives combat XP, drops, and passive Prayer — a triple win.

Marketplaces like GP Trillionaire exist for this exact reason: to convert real-world money into in-game gp quickly so you can skip the low-value gp grind and focus on the training content you enjoy. You can view live gold rates to see current prices before deciding. Always verify current Grand Exchange prices and check the wiki for up-to-date XP rates and requirements.

Boosting services for Slayer or Prayer are another option, but they carry account security and trust risks. Only use services with strong reputations, and never share your password through unsecured channels. The safest path is to buy gold and do the training yourself, keeping full control of your account.

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Verdict and Next Steps

The bonecrusher necklace with elite Morytania Diary is the best zero-time Prayer training method in OSRS. It turns every bone drop during Slayer into full bury XP, stacks with ash sanctifier and ectoplasmator on relevant tasks, and requires almost no extra attention. It will never replace gilded altar or libation bowl for burst XP, but over a full Slayer grind it is the difference between 77 Prayer and 90+ Prayer without ever training Prayer actively.

Your next move depends on your account:

• If you don’t have the elite diary yet: Work on the Morytania elite requirements, and use active offerings for your immediate Prayer goals. Check the wiki for exact diary tasks.
• If you have the diary but not a bonecrusher: Acquire a bonecrusher or bonecrusher necklace, stock up on ecto-tokens, and charge it before every Slayer task.
• If you already have everything: Add an ash sanctifier and ectoplasmator to your loadout, and alternate passive Slayer with libation bowl or gilded altar sessions when you need a level quickly.
• If you need gp for supplies: Compare your gp-per-hour from bossing or Slayer against buying gold. Sometimes the honest answer is to skip the grind and buy the bones.

Sources: Pay-to-play Prayer training - OSRS Wiki.