Deep Crafting Tree in MMORPGs

Deep Crafting Tree
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A deep crafting tree can flexibly and clearly integrate an unlimited number of craftable items. It accurately stores individual crafting skills for each item and builds an implicit hierarchy. Furthermore, the tree provides a natural progression without deadlocks.

Crafting links different player groups and the MMORPG economy’s spine. Therefore you must keep crafting relevant and create many interesting decisions for players. That’s what the deep crafting tree is for.

Table of contents

Why a deep crafting tree?

Traditional crafting systems in MMORPG have a similar structure. A product is crafted by combining a number of raw materials or other products.

Material requirements to craft a product.

The availability of materials determines the ability to craft a product.

Implicit hierarchy in a crafting system.

When higher-level products require lower-level products as ingredients, there is an implicit hierarchy in such a system.

However, players can skip steps in the hierarchy when they buy higher-level materials from other players. Therefore, most systems enforce a skill barrier. Each pattern requires a certain skill to learn. Therefore, such systems have an implicit and explicit hierarchy.

Implicit and explicit hierarchy in a crafting system.

In most cases, the skill in crafting increases with the number of crafted items. Advancing higher-level skills requires higher-level craftings.

These crafting game mechanics work very well. The deep crafting tree advances it. It addresses the following three problems:

  1. flexibility: when all items in a game are craftable, integrating them all can be ambiguous
  2. accuracy: differentiate between the crafting skill (e.g., “swordsmithing”) and the skill to craft a particular item (e.g., “craft wooden sword”)
  3. progression: provide a natural progression without deadlocks.

To make the tree work, you require your MMORPG items to have a particular structure.


Where items come from

Items enter the game in two ways:

  1. loot from defeated creatures or chests
  2. crafting players

So there are looted items and crafted items.

Difference between looted items and crafted items

There are fundamental differences between looted items and crafted items. Both can be identical in their attributes.

looted itemcrafted item
name that relates to its look or its originname that relates to the production method
“Azimo’s Iron Beheader”“Yellow Iron Sword”
crude, exotic or fantastic looksimple look
multiple variantsone variant
cannot be craftedcan be crafted
can be deconstructedcannot be deconstructed

Looted items may exist in multiple variants found in completely different places.

Item shadows

Item shadows mean that each craftable item may have several equivalents of looted items. These shadows have identical attributes yet different names and look.

Shadows of the Yellow Iron Sword.

To get a pattern, players have to deconstruct a looted item. Deconstructing a looted item gives the pattern of the underlying crafted item. Deconstructing The “Ogre Plane” gives the player a pattern for the “Yellow Iron Sword”.

Patterns are tradeable.

When your game uses item decay, you might limit deconstructing items to decay above a certain value.

Therefore, item shadows are a solution to remove redundancy from the crafting. This enables the flexibility of the deep crafting tree.

However, the player might not learn the crafting from the pattern. What the player can learn depends on his crafting skills. After all, the player cannot simply grabble an epic end-level pattern once and – Bing!- craft epic swords.

So, what exactly does the player get? The deep crafting tree tells.

Structure of the deep crafting tree

Simple deep crafting tree

A deep crafting tree is a game mechanic that implements a crafting skill progression. This mechanic demands that there are unique item categories. Each item category has a clear item hierarchy.

Simple deep crafting tree for bags. The root is left, the treetop is right.

The tree contains all craftable items of one category. In its root, there is the simplest item. In its treetop, there is the best item.

Simple deep crafting tree for swords.

Branching deep crafting tree

A deep crafting tree can have several items of the same level. That is called branching. Like a real tree, two branches don´t re-unite on higher tree levels.

Branched deep crafting tree for swords.

Branching enables you to integrate non-linear item characteristics. Two items of the same item category may have the same item level yet different item attributes. One item might add fire damage, and the other item acid damage.

Advance in the deep crafting tree

Not enough skill

Adam loots Azimo´s Iron Beheader. He wants to advance his swordsmithing career. Therefore he deconstructs the item and gets the patterns for Yellow Iron Sword. Read Item Shadows if you don´t understand why.

Eagerly, he tries to learn the pattern. The previous pattern’s crafting skill must be higher than a skill barrier to enable learning a new pattern. In this example, the skill barrier is 25 %.

Not enough skill to learn a new pattern.

Therefore, Adam cannot learn a new pattern at the moment. As promised, the deep crafting tree can accurately differentiate between the crafting skill (e.g., “swordsmithing”) and the skill to craft a particular item (e.g., “craft wooden sword”). More precisely, the overall crafting skill is implicit in the single skills to craft particular items.

Pattern downgrading

To learn the pattern, Adam crafts more Wooden Swords. This increases his skill.

Yellow Iron Sword pattern: players cannot skip levels.

So finally, he can learn the pattern. The game warns him: using this pattern will teach you Yellow Bronze Sword. Something Adam never heard of. And it has worse stats than the item of his pattern. Why is that so?

Pattern downgrading.
Pattern downgrading.

The player cannot skip a step in the deep crafting tree. So when the player wants to learn a pattern, the game walks down the tree until it finds a known pattern. This is called pattern downgrading.

You learn something inferior because you are not high enough advanced in the tree. In Adam’s case, this is the Yellow Bronze Sword. As promised, the deep crafting tree has no deadlocks. Rather, it provides are a natural progression.

Adam decides he doesn´t want to waste his pattern this way. Therefore he puts it in the bank for later use.

Regular Learning

Later, Adam buys a pattern of Yellow Bronze Sword. He learns it and crafts a lot of Yellow Bronze Swords.

Regular learning the Yellow Iron Sword pattern.

Now it is time to learn the Yellow Iron Sword. Adam gets the pattern from the bank and learns it. Now he can craft Yellow Iron Swords.

How to craft the first item?

Teachers sell the ability to craft the root item of a deep crafting tree. Teachers never teach higher-level craftings because this would corrupt the deep crafting tree’s mechanism.

Advance in crafting skills

Advance in crafting skills means becoming better at crafting a particular item.

The crafting skills barrier

The crafting skills barrier describes how high the player´s crafting skill needs to be before learning the next pattern. In the example above the skill barrier was 25 %.

High or low skill barrier

The higher the skill barrier, the slower and more expensive leveling crafting will be. A very high skill barrier will force players to craft large amounts of the same item. This will feel meaningless and tedious. Furthermore, it will flood the economy with crafted items. Also, you have to decrease the raw materials needed for crafted items. Otherwise, crafting will not be worth it at all.

A low skill barrier will enable crafting progression with almost no crafting. Many players will maximize their crafting skills because it is fast and cheap. You can increase the raw materials needed for crafting items because it is rarely done.

Your game should be in the middle of these extremes. So a skill barrier in the range of 25 % might be ideal.

The Academy

There is a contradiction in crafting that limits your options regarding crafting raw material costs:

  1. The raw material costs must match the value of the crafted item.
  2. You must produce many items to increase your crafting skill.

The problem comes with items of high value. Requiring players to craft countless epic swords is not only tedious. It also destroys the rarity of these items. Making the items cheaper to craft has the same effect on rarity.

The Academy comes to help out. Players can go to the Academy and agree to a deal: They have ideal crafting conditions in the academy. Crafting an item in the academy lets players advance their crafting skills faster. However, the academy keeps the crafted item as payment.

As a result, players need to craft fewer items to level. The raw material costs and items’ rarity can stay high.

Advantages of high crafting skill

Add advantages to crafting when the crafting skill is high. This can be that players require less raw materials with increasing crafting skills. Therefore, it is worthy for a player to increase his skill for a particular item beyond the skill barrier.

Add advantages to crafting when the crafting skill is high.

Can you think of any other advantages?

Leveling the crafting skill to reach the skill barrier should be possible by crafting a few items.

However, leveling above the skill barrier should be hard and require the player to craft many items. This gives players meaningful options: focus on advancing the deep crafting tree or focus on advancing the crafting skill of a particular item. Over time one choice or the other will be better.

Deep crafting tree and expansions


Expansions are essential for an MMORPG. The deep crafting tree can grow by adding patterns at the treetop when the maximal level of items in the game increases.

Expanding the height of a deep crafting tree with higher level items.


Also, the crafting tree can expand with items of the same item level.

Expanding the width of a deep crafting tree with items of the same level.

This is when the expansion adds items without increasing the maximal item level.


Independent from these possibilities, you can also add new versions of the same item with different names and look.

Adding item shadows means expanding the depth of a deep crafting tree.

The deep crafting tree is expandable in height, width, and depth.


The deep crafting tree implements a natural crafting skill progression that is flexible and expandable in height, broad, and depth.

  • flexibility and clearness: each craftable item may have several equivalents of looted items
  • natural progression: when the player wants to learn a pattern, the game walks down the tree until it finds a known pattern
  • accuracy: advance in crafting skill means to become better at crafting a particular item
  • an academy can keep the raw material costs and items’ rarity high

Game design considerations.
Design Doris

Crafting is a link between all players and touches the MMORPG core. Keep it relevant and interesting.

(Last Updated on May 2, 2021)

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