Crafting in MMORPGs is a troublesome, complex issue. The ability for players to create things with which to equip, clothe, and house themselves is difficult for developers to implement, and many companies have tried a variety of ways to try and address this feature. My first real experience with crafting in MMORPGs was in Star Wars: Galaxies, and that has colored my view on crafting ever since. This is not to say that SWG had a perfect system, but it came closest out of all the MMOs I've played. This is chiefly due to the following eight factors. This is a fairly long read, so grab a cup of coffee, put on your bunny slippers, and sit back in your favorite chair.
I: Item Decay
In early Star Wars: Galaxies, items decayed over time and would eventually become unusable. If an item ever became unusable, it was done - you couldn't repair it, like in other games since. Even if you repaired items before they became unusable, you were never able to bring it back to full durability. The item's maximum durability decreased every time you repaired it. The effect this had on the player economy was to keep crafters in business perpetually. There was always a demand for things like weapons and armor, because those players who engaged in combat were always wearing out their gear. Vehicles, after they were added to the game, similarly decayed and could be outright destroyed. I remember distinctly being very upset whenever I lost a swoop, since that meant a long walk back to town and around 20,000 credits spent to replace it. This system of item decay has never been replicated in any other game.
II: Customization
When crafting an item in SWG, you were able to choose its final appearance in a few ways. Clothing was the most customizable, with a variety of colors available. Weapons could have different models with different barrels (in the case of blasters). Armor, similarly, could have multiple colors. The skill level of the crafter determined to what degree the item could be customized. This meant that high-level crafters were in high demand for those players who cared about appearances, and could charge more for their services. Oddly enough, item customization as far as appearance goes has never been done very well in MMORPGs. That crown goes to Blacklight: Retribution, a free-to-play online FPS with excellent weapon customization. The game lets you change barrels, stocks, triggers, bodies, accessories, and colors of all of the above.
III: Experimentation
Part of the crafting process in Star Wars: Galaxies allowed you to improve the quality of a crafted item before finishing it. You could choose multiple areas to try and improve; in the case of blasters, for example, you could experiment on increasing damage, range, or accuracy. Depending on the crafter's skill and the materials used to create the item, experimentation could greatly enhance, marginalize, or utterly wreck a crafted item's stats. No other game since has implemented an item-modification system quite like this.
IV: Resource Variation
Every resource in Star Wars: Galaxies had a unique set of statistics. Different kinds of item recipes used different sets of these statistics to determine the item's qualities. Additionally, resource spawns in the game universe varied by planet and were in limited areas and densities. Every week, a new set of resources would spawn throughout the universe, and the old spawn areas were gone forever. This meant no resource would ever appear more than once, and really good resources thus became very precious. Because of this system, harvesting itself became a lucrative business. Some players devoted multiple accounts just to collecting the best resources and selling them to other players. Some games have come close to this kind of variation. Oddly, the one that has nearly replicated SWG's resource variation is an MMOFPS rather than an MMORPG - Firefall. Like SWG, Firefall's resources appear for a limited time, have multiple statistics that are randomly generated, and never appear twice.
V: Automated Harvesting
This feature made a world of difference to the crafting economy. Players could craft automated harvesters and place them in the world. Then, the player that placed the harvester chose one of the resources available in that area from the harvester's command panel, and it would steadily recover a certain amount of that resource every minute or so. Harvesters required fuel to operate, which itself was a resource that could be harvested. Harvesters could be experimented on and improved in multiple areas, just like other items, and so a niche market existed just for harvesters. Harvesters had an administration list that allowed the owner to designate other players as being able to turn on, fuel, and change the target resource for them. Since every character only had 10 plots, and each harvester took 1 plot, in order to field large numbers of harvesters a player would need to either have multiple accounts or engage the services of other players. This further supported a niche market for harvesting. No other game has ever had automated harvesting, although the idea of harvesting as a lucrative in-game “profession” has been done also by EVE Online.
VI: Mass Production
In addition to automated harvesters, players could craft and place factories. These buildings took power and maintenance credits like harvesters. They also had a hopper of limited space for ingredients and for generated items. At the end of the crafting process, players had the option of creating a blueprint instead of a finished item. They could take that blueprint, and stacks of the ingredients used to produce the item, and place them in a factory. Once the factory was turned on, it would generate copies of that item until it ran out of power, maintenance credits, ingredients, or available space in the output hopper. Not only was this a godsend for crafters looking to mass produce items for sale, it also was a requirement to create certain items. Many of the higher-end crafted items required “identical” components - that is, stacks of items created by a factory from a blueprint. No other game has ever done this. While not a requirement for a good crafting system, it's necessary to support sandbox games that rely on player crafted items, since small populations can still create large numbers of items.
VII: Loot Sucks
Players that chose to engage in PvE gameplay in SWG relied heavily on the crafters. Items looted from humanoid NPCs were never very good, and creatures had no loot at all until later in SWG's life. This meant that player-crafted gear was the only option for combatants, and required players to work together in order to play the game. Lone wolves rarely did well. No MMORPG other than early SWG has ever done this again. Even SWG itself later did away with this, preferring to give players vendor trash, crafting components, and crafting blueprints.
VIII: Non-Instanced Housing
Non-instanced housing itself is not particularly relevant to crafting. However, the way it was implemented in SWG makes it vital to that ecosystem. All player-owned buildings were player-crafted. Harvesters, factories, houses, guild halls, city halls, shuttleports, med centers, and taverns were all created by players. And they were very expensive to build, at least at first. When player cities were first added to the game, I was my guild's Architect (an in-game profession dedicated solely to crafting buildings). Leading up to the release of player cities, we stockpiled large quantities of the resources needed to build the various city buildings. As soon as the update went live, I sat at my structure crafting station and put together a city hall deed, and we rushed to be one of the player cities on our planet. At the time, only ten cities could be established on any given planet. We were too late to be one of the cities on Corellia, so we hurriedly traveled to its moon, Tarus, and set down roots a kilometer northwest of the Imperial outpost there. In order to craft that city hall, and any high-end items, I need a personal crafting station of the appropriate type for the item. Public crafting stations couldn't stand in for them. Personal crafting stations needed to be placed in a player house, and they took a number of advanced components. They had a direct impact on the final quality of items, so all serious crafters absolutely had to have access to a house with all the different types of personal crafting stations. This led to most guilds having dedicated “crafting houses” that were so equipped, with backpacks placed in them with large quantities of the various resources needed for crafting. No other game has ever had non-instanced housing with such a rich connection to player crafting - both in the building and usage of them. That brings me to the end of my list. I wish I could find a game that had all of these features. SOE may be bringing all of this back with EQ Next, but until we get a science-fiction MMORPG that has all of the above, I don't think we'll ever come close to what Star Wars: Galaxies had. Here's to hoping, though!