The game is set in a fairly standard fantasy land called Wurm. There are no classes and no choices to be made at player generation save for gender. Up until the big update on December 12th, there was only one model per gender. There are no named NPCs other than the deities, and no fixed questlines.
All skills are developed by usage. Anything in the world can be made or crafted by player efforts. Trees can be cut down and turned into containers, buildings or firewood. Rocky terrain can be mined to access metal ores or for the rocks themselves, which can in turn be made into bricks for buildings and decorations. Even dirt can be dug and relocated to reduce and increase the height of terrain. Want grass on a dirt tile? Plant a tree, bush or flower on that dirt. Don't want grass? Dig it away, pack it, or pave over it. A series of written and unwritten rules prevent players from inconveniencing each other with rampant terraforming.
Players can also engage in combat like most games in the same genre. Combat in Wurm is text-based, with skill level and other factors calculated to give the combatants' hit probabilities and damage. The type and quality of weapons and armor plays an important factor here. In addition, creatures both mundane and fantastic can spawn at inopportune moments to attack unwary players; an important survival strategy is to identify where exactly these spawn points are.
Interesting fact: Notch, best known as the creator of Minecraft, was a member of Wurm Online's development team before leaving to do his own thing, and the rest as they say is history.
Wurm Online provides examples of:
- 2½D: Hard to notice at first, what with the open sky, mountains, and caves. The limitations are only really felt when conducting mining operations. You can mine up or down as you please, but if two tunnels of different heights were to cross, a dropshaft is created regardless of how far apart you thought they were vertically.
- A Homeowner Is You: You can even build it yourself. They range from tiny hermit shacks out in the woods to impressive stone mansions with paved compounds surrounded by stone walls and street lamps.
- An Interior Designer Is You: Once you get a house, you can also acquire things to fill it with. These can be useful items such as ovens and containers, or decorations like chairs and tables.
- Anti Poop-Socking: Sleep bonuses, where you can double your skillgain. This works by clicking on a bed you own and choosing "Sleep", which will then log you out. Until the next time you log in, your character accumulates sleep bonus at a rate of 1 hour per 24 hours spent "sleeping" (maximum 5 hours of sleep bonus).
- Breakable Weapons: In fact, everything is breakable. Items accrue damage by use and will also decay over time. Fortunately all items can also be repaired, but with a proportionate reduction of quality.
- Bribing Your Way to Victory: In addition to the monetary costs of Premium, players can spend even more real money on in-game currency. The only other way to acquire in-game currency is by trading with other players, which is never a sure thing. This money can be used to quickly buy high-quality items from more skilled players, establish settlements (claiming otherwise public land as yours), and maintain those settlements (which will be disbanded if you don't, no refunds).
- It must be noted that for some reason it is cheaper to buy Premium with real money than it is to pay the equivalent amount of in-game currency. To elaborate, buying two months of Premium with real money costs 10 Euros. Buying one month of Premium with in-game money costs 10 silver, and it costs 1 Euro to buy 1 in-game silver. Perhaps the Premium experience is meant to be easier to access than having extra spending money? On the other hand, it makes it harder for business-minded players to maintain Premium with just trading.
- Cool Horse: Horses can be decked out in bardings of various materials and colors, and equipped with horseshoes, saddles and bridles to make them faster or easier to ride.
- Cosmetic Award: Achieving a certain level in a skill can add titles to your name, such as "Mason", "Master Blacksmith", etc.
- Crippling Overspecialization: Technically possible due to the sheer quantity of grinding needed to increase a single skill. In practice, very difficult to achieve alone and due to the way skillgain works there's nothing lost from improving other skills.
- Death Is a Slap on the Wrist: In the Freedom cluster expecially, where you will respawn at your village or tent with a minor experience loss in a few skills (and 10 times less if you die at your deed or village) and you have an ample window of time to track down your corpse and reclaim your items, or decide when to release it to have someone else get them for you. Slightly less so in the Epic and Chaos islands, where anything you have on you is fair game for whoever killed you.
- The penalties for death can be further dampened by the Bag of Keeping, which lets you keep certain items with you when you die; certain spells which let you retrieve your corpse from anywhere, and the Path of Knowledge passive skill which negates almost all skill loss.
- Enlightenment Superpower: Long hours of meditating can grant you diverse powers such as faster healing, teleporting, and blasting holes in the heads of your enemies with the power of your mind.
- Fluffy Tamer: With sufficient animal taming skill, one can tame dangerous creatures such as bears and crocodiles. As an added bonus, bears can be ridden into combat.
- Glass Cannon: Hell hounds. They're the mob with the longest aggro distance, and are fast enough to close that distance very quickly. They will die with a few solid, well-aimed hits, but can also inflict enough damage to kill the average fighter in a few moments.
- GoldSilverCopper Standard: Uses a Gold > Silver > Copper > Iron system, with 100:1 ratios across the board, but injects a bit of realism by restricting gold and silver coins to very high-value transactions; few players will ever actually see a gold coin.
- Item Crafting: Taken Up to Eleven; a lone player could potentially craft an entire village from the starter tool set and access to raw materials. The game even touts it's focus on player-made items and environment. Furthermore, almost all crafted items can be improved, increasing their quality using the same tools and raw materials used to make them. Most non-bulk items above a certain quality will bear the maker's signature, which becomes more legible the higher the quality.
- Jack of All Trades: A possible outcome for players looking to be self-sufficient.
- Medieval European Fantasy: Slightly more Mediterranean in feel than usual, with olive and lemon trees and wine instead of beer, but still qualifies.
- The crop selection contradicts it, by sporting corn, tomatoes, peas, potatoes and even cocoa beans. It's even lampshades in that examining some of these crops will prompt the comment "Where did this come from?"
- Perpetually Static: Averted, in line with the focus on a player-driven world. Settlements can be founded and disbanded, public highways built to connect places of interest, walls erected to block mob spawns, forests leveled to make potato farms, and so on.
- Play Every Day: To the point of being kind of obnoxious. Go longer than 24 hours between tending a particular crop-tile and it dies. Buildings, particularly the wooden ones that free players are restricted to, will fall apart entirely within a week if not maintained. And this isn't a game you can play on a cheap tablet either.
- Player-Generated Economy: In the forums and chats players can be seen offering and asking for various goods and services. The only guaranteed buyer for goods is an NPC Trader, whose contract costs 50 silver to acquire. It also takes time for his money supply to refresh. Everything else runs on supply and demand, though players can access a "get price" for any items they examine which is presented as "a Trader would pay x for this". For rare items at auction, the prices can escalate quickly with much profit to be had.
- Regenerating Health: Very light wounds, such as those inflicted by a weak animal through high-quality armor, will heal completely in 10 minutes, meaning a player can go from near-death to good as new in a few seconds provided they don't get hurt any more afterwards.
- Religion Is Magic: While followers of the deities have modest benefits and minor restrictions, priests gain access to a wide variety of spells in return for more restrictions.
- Scenery Porn: Besides mountains and oceans being a generally cool place to watch over, the world also changes appearance with ingame seasons, and celestial bodies orbit it. There also are celestial phenomenons like rainbows and eclipses.
- Subsystem Damage: Each body location can be hit, with each wound being tracked separately. However, Critical Existence Failure occurs when the total damage suffered exceeds your health. So you could die from a few bad wounds or dozens of light ones.
- Tech Points: Skills increase by usage and only by usage. Certain skills have sub-skills attached to them; increasing a sub-skill increases the parent skill, while increasing the parent skill improves the success rate of all sub-skills. Extending this system, all skills have characteristics associated with them such as Body, Mind, and Soul. Increasing an associated skill increases a characteristic, while a high characteristic increases the success rate with all related skills.
- Wax On, Wax Off: Even mundane tasks such as farming, building or working will steadily improve the Body, Mind and Soul characteristics, which have a sensible impact on combat prowess. Also, simply using a tool improves its performance as a weapon: a character who has nothing but dig for weeks will have a really good fighting chance with it.
- Wide Open Sandbox: The main website even proclaims the lack of quests as a feature. Compared to your standard MMORPG, interacting with other players in Wurm Online goes a long way to adding some variety and challenges. Join a settlement, found a settlement, trade goods and services with other players, take part in community projects, and so on.
- Wizard Needs Food Badly: The game tracks hunger and thirst, the lack of which won't kill you (yet) but reduce your stamina regeneration. A low hunger bar also prevents you from doing heavy work like mining and digging. In addition to outright hunger, the nutritional value of your food is also tracked. Higher nutrition increases your skillgain and slows the rate at which you get hungry.
- As a kind of safety net, when the hunger bar gets too low the player will automatically fast, filling the hunger bar but consuming fat reserves. A player who continues to not get food will eventually run out of fat reserves and remain in a perpetual state of weakness.