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Release date 25 January 2016 (Update)
Members Yes
Level 1 Invention, 80 Crafting, 80 Divination, 80 Smithing
Spellbook Normal,
Type Skilling
Experience 0
Runes None
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Disassemble is an Invention ability unlocked during the Invention Tutorial, located under skilling spells. When used on an item, the item will be disassembled into materials which can be used in Invention. It requires 1 Invention (which in turn requires 80 Divination, Crafting, and Smithing) and the Inventor's Tools (which are automatically added to the tool belt during the tutorial) to use, but has no cost. Disassemble can also be used by dragging the item over the Invention icon in the inventory; additionally, tool, weapon, and armour gizmos can be disassembled using their right-click option.

Both noted and unnoted items can be disassembled. Some items disassemble in batches - for example, most ammunition disassembles in batches of 50. Up to 60 batches (normally 60 items, or 3000 ammunition, etc) will be automatically disassembled per use of disassemble.

Analyse can be used to know what materials the item can be disassembled into, but using it is not a requirement to disassemble the item.

Disassembly takes 2 game ticks (1.2 seconds) per batch, giving an absolute maximum of 3000 sets per hour.


Almost all the necessary information for disassembly is provided by the Analyse ability. There are essentially two steps to the mechanics of disassembly: how the analysis information is generated, and how that list, over many disassemblies, is turned into a distribution of those materials.

Within analysis, several key points of information are given:

  • The number of items disassembled per action
  • The junk chance of the item
  • The number of materials obtained per disassemble ("chances for materials"), excluding special components
  • The list of possible materials to be obtained from disassembling the item, with special components at the top, then listed in decreasing probability order

Additionally, upon disassembly, Invention experience is gained. Repeated disassembly of the same item will give a distribution of the possible materials (and junk).


In general:

  • Items that can be alchemised can also be disassembled (though there are many counterexamples)
  • Items that cannot be alchemised also cannot be disassembled (again, many counterexamples)
  • Augmented items can always be disassembled, even if their non-augmented versions cannot be

Disassembly categories

Almost every item falls into a group of items which disassemble into the same list of possible materials; for example, rune helms, rune platebodies, and mithril helms all disassemble into the same list of possible materials, just with varying material and junk chances. This means that they are in the same disassembly category. Disassembly categories don't have visible in-game names, so we have given them our own, logical names on the wiki - e.g. the category for the above items is melee armour.

Within each category there are essentially subcategories which vary the material number. For example, within the melee armour category there are several subcategories, including: melee helm, which give 6 materials; melee body, which gives 8 materials; and melee boots, which give 4 materials. Subcategories are mainly the intersection of an item's main category and an item's slot and/or use.

The key point is that if the list of possible materials is different (excluding special materials), it is a different category.

Determining an item's category

An item is given a category by the game the following points (in loose order of precedence):

  • Manual category specification
  • If the item is equipable:
    • Assign category based on offensive and defensive stats, assign material number based on slot/hand (e.g. armour, weapons)
    • If it has no class nor stats, assign clothing category (e.g. pink skirt)
  • If it is a craftable item, use the primary required skill to determine category (e.g. food, potions)
  • If it is a gatherable material, use the primary gathering skill to determine category (e.g. logs, ore)
  • If it is a crafting material with no gathering skill, use the crafting skill to determine category (e.g. leather)
  • If all else fails, assign default category

On the player's end, the easiest way to find an item's category is to analyse it, then look that up in the known categories.

Special materials

Whether an item gives special materials are essentially all manually defined. Special materials are given in addition to the normal number of materials. Special materials are almost always rare materials which require additional research to utilise in a gizmo.

Most of the time, if special materials are given, they are always given. However, there is a not insignificant number of items which give special materials sometimes (and if they do, they tend to be one of the material each time); if a special material is given sometimes, the other result is getting nothing (you won't get junk or any other material instead). Unfortunately, the only way to know how many special materials are given, and if it is always given, is to disassemble several of the item.

An interesting exception to this is non-attuned crystal equipment. Crystal equipment will always give one special material, but the material can be either crystal parts or Seren components, with the distribution being heavily weighted toward crystal parts.

Item level

Item disassembly level - not to be confused with equipment tier or any other use of 'level' - is an internal number related to each item which determines both the base junk chance of the item, and the experience given upon disassembly. The level is directly related to how the category is determined - the equip requirement, the crafting/gathering level, etc. It is an integer with minimum 1 and (current) maximum of 100.


The experience $ x $ given by a normal item is a function of its item disassembly level $ l $, and a "goodness" variable $ g $:

$ x = \max(\left \lfloor 0.03 \times l \times g \right \rfloor,0.1 ) $
$ g = \begin{cases} 10 & \text{if good} \\ 1 & \text{otherwise} \end{cases} $

Items that are defined as good are most equipable items, with some exceptions (e.g. signs, ammunition), and some non-equipable items (e.g. unstrung amulets). Goodness (generally) applies to categories as a whole.

For example, a rune platebody requires level 50 Defence to equip, so its level is 50. As it is an equipable item, it is considered "good".

$ \max(\left \lfloor 0.03 \times 50 \times 10 \right \rfloor,0.1 ) = 1.5 \times 10 = 15 $

All items give at least 0.1 experience. Level 1 items, for example, are calculated to give 0.03 experience, which rounds down to 0. The $ \max $ function corrects this, giving it 0.1 for disassemble.

Augmented items give this experience in addition to experience based on its item level.

Junk chance

Main article: Junk § Calculation

An item's junk chance depends on its item disassembly level and your current junk chance reduction. Junk chance is split into three sections: levels 1 to 74 follow a linear formula, levels 75 to 89 roughly follow a quadratic formula, and levels 90 and higher never give junk.

Augmented items level 4 and higher never give junk when disassembled.

Augmented items

For full tabulation of experience of disassembling an augmented item, see Calculator:Equipment experience by tier
Augmented disassemble

Prompt for disassembling a tier 80 level 10 item

Disassembling augmented items would also destroy the augmentor. They behave differently from other items when disassembled past level 1. Level 1 augmented items will give the exact same materials and experience as the unaugmented version. Level 2 items and above have additional experience amounts and different behaviour, as described in the table below.

Disassembling an item gives different experience based on its tier, with the normal value being for tier 80. Tier 90 items give 15% more experience; tier 70, 15% less. For tier 75 items give 7.5% less experience and tier 85 items give 7.5% more experience. Tier 1 items count as tier 25 for this experience, giving 17.5% of tier 80 experience.

$ \text{XP} = \text{Base XP} \times \left (1 + 1.5 \times \frac{\text{Tier}-80}{100} \right) $
Invention experience (tier 80) Item effects
Disassembly Siphon GP/XP
1 0 0 N/A N/A
2 1,160 9,000 Disassembling this item has a 50% chance to return installed gizmos.
3 2,607 27,000 Disassembling this item gives double materials.
4 5,176 54,000 9,000 32.99 Disassembling this item never gives junk.
5 8,286 108,000 27,000 10.0 This item drains 10% less charge when used.
6 11,760 144,000 54,000 5.50 Disassembling this item gives triple materials.
7 15,835 198,000 108,000 2.75 Disassembling this item gives an extra random uncommon material.
8 21,152 270,000 144,000 2.06 Disassembling this item returns all installed gizmos.
9 28,761 378,000 198,000 1.50 Disassembling this item gives quadruple materials.
10 40,120 540,000 270,000 1.10 Disassembling this item gives the maximum extra Invention XP.
11 57,095 378,000 0.79 N/A
12 81,960 540,000 0.55 Siphoning this item gives the maximum extra Invention XP.
13 117,397 0.27 Siphoning this item has a 50% chance to not consume the siphon.
14 166,496 This item drains 12.5% less charge when used.
15 232,886 This item can now be used with an Equipment separator.
16 320,080 0.00 Siphoning this item no longer consumes the siphon.
17 432,785 Using the Equipment separator on this item has a 25% chance to not consume the separator.
18 575,592 This item drains 15% less charge when used.
19 753,631 Using the Equipment separator on this item has a 50% chance to not consume the separator.
20 972,440 Helpful perks will activate 10% (multiplicative) more frequently. See Perk benefits for a list of perks that are known to be affected.

Material distribution

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The process by which the resulting materials are given upon disassembly is as follows:

Here, the term "roll" is used to mean randomly generate a number and compare against the relevant chance
  • For each of the number of materials:
    1. Roll against junk chance
    2. If not junk, roll against the material distribution and give 1 of the relevant material
  • If the item gives special components always, give them; if it gives them sometimes, roll against special chance

Thus, there are two steps to determining the chance of getting a specific material from an item: the junk chance, which is clearly stated in analysis, and the material distribution, which is obfuscated.

However, with large sample sizes of non-junk materials, a material distribution can be found. For example, shortbows have distribution:

Material Stated chance Chance
Stave parts Stave parts "Often" 35%
Tensile parts Tensile parts "Often" 30%
Flexible parts Flexible parts "Often" 30%
Precise components Precise components "Rarely" 3%
Dextrous components Dextrous components "Rarely" 2%

The chances given in analysis ("often", "sometimes", and "rarely") do correspond to a range of chances. Rough estimates suggest that rarely is under 5%, sometimes is between 5% and 15%, and often is more than 15%.


Not all items can be disassembled:

  • Attempting to disassemble most non-disassemble items will prompt the message: "That item cannot be disassembled."
  • Attempting to disassemble crystal seeds prompt the message: "You cannot disassemble crystal seeds." This does not apply to charged Crystal teleport seeds.
  • Attempting to disassemble living items such as dreadnips and red chinchompas will prompt the message: "You monster! You can't disassemble a living thing."
  • Attempting to disassemble Tokkul will prompt the message: "The TzHaar would not approve if you disassembled TokKul."
  • Attempting to disassemble certain rare items (Off-hand rubber chicken, Blue marionette) or high valued items (Blue partyhat) will prompt the message: "You could not bring yourself to destroy this rare item."
  • Attempting to disassemble certain items (Amulet of ranging, Cat antipoison) will prompt the message: "You could not disassemble that item."
  • Previously, attempting to disassemble certain bolt tips used to prompt the message: "You cannot disassemble bolt tips." Similarly, some arrowheads prompted the message: "You cannot disassemble arrowheads." This is no longer the case as both of these item categories can now be disassembled as of 8 February 2016.


  • Pets such as ravens will only yield the default "That item cannot be disassembled." message despite being a living thing. On the other hand, salamanders, seeds, and saplings can be disassembled.
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