YGGDRASIL

"A DMMO-RPG where strength is not everything."
 * - Creators describing the game, YGGDRASIL.

YGGDRASIL (ユグドラシル Yugudorashiru) is a fictional online game in OVERLORD series. It is a DMMO-RPG (Dive Massively Multiplayer Online Role Playing Game) developed in Japan.

Infamous as the game is, its degree of customization made YGGDRASIL so popular that at one point in Japan, the word "DMMO-RPG" was practically synonymous with YGGDRASIL.

On the other hand, the game has been active since its release in 2126 AD until 2138 AD. Because in the current year, 2138 however, the game's community by then already lost the vibrancy it once had. As a result, the remaining players still playing YGGDRASIL have met their final day online.

Introduction
YGGDRASIL is a DMMO-RPG released in 2126 by a Japanese Developer. According to the developers' website, YGGDRASIL was a game of exploration, and so many things were mysteries left unknown for players to discover on their own or in groups. It was a game where all you were told was the controls before being thrown into the deep end. In other words, the special thing about YGGDRASIL was the incredible amount of freedom given to players, compared to any other DMMO-RPGs out there.

YGGDRASIL needs an exclusive console to play, which records logs for a week. Though the game is a full virtual reality one, in accordance to physical laws, it does not provide a sense of taste and smell, and has a limited sense of touch. Due to the lack of such technology when the game was developed, facial expressions and artificial intelligence are not supported.

The most distinctive feature of YGGDRASIL is its flexible system to let player make choices freely. Players can select numerous races and jobs and various tools allowing for customization in the game. If a player were to use creator tools that were sold separately, one can freely alter the appearances of weapons and armor, interior data, character visuals, and advanced settings of their in-game residences or home. It seems that the customization system is really far-reaching and broad, even extending to basic programming.

Incidentally, in YGGDRASIL, one could equip magic items in the following slots: head, face, body, three pieces of jewelry apart from one’s rings, underclothing, arms, hands, left and right rings, waist, legs and feet. Even a suit of full plate armor only counted as taking up the body slot. A player could tinker with the game's database by using the creator tools and form original items. One could also buy appearances within the DMMO-RPG. Through doing this, a player is able to create an unlimited variety of original items.

On the other hand, there are player characters from different races who can't make facial expressions in the game. In the first place, YGGDRASIL characters had no expressions to begin with. A regrettable deficiency was that one’s avatar could not change expressions to match one’s voice. At the same time, a character’s mouth would not move with their words. The basic premise was that external appearances were fixed.

Because of that, facial expressions were impossible to design. Though it does seem somewhat possible for a player's expression to change accordingly by their own words. For example, it would not be that difficult for humanoid players. However, it is impossible to do so, since writing macros to move the faces of demi-humans and heteromorphic beings was extremely difficult.

Instead, players can used their bodily motions to compensate for the lack of facial expressions in YGGDRASIL. Not only that, but a player can also touch their console to select various faces from one of the emoticons, using it as a way to identify the feeling and mood they have right now.

Also, the game had a system where players could even pay a fee in order to participate in a lottery to win a rare item. This would include a type of cash gacha within the game where players have the opportunity to cash in money with the chance of winning a prize.

Moreover, the cosmetic skins released were only available in limited quantities. If one missed out on them, it would be extremely difficult to acquire them afterwards. As such, players tended to buy up any new cosmetic item that looked halfway decent.

While so, YGGDRASIL was a game where information itself had value. Like the case with World Item, the number of people who freely shared newly discovered information with others was small and they usually must pay a price if one wants to know about it. The same could also be said with classes such as Eclipse that possesses a secret trump card. Although a lot of information had already been collected, most of it pertained to dungeons or other locations, and it was estimated that only 30% of the nine worlds had been mapped so far. During the final years of YGGDRASIL, the chances of reliable information being made public on the web was rather high.

There are endless discoveries (special classes, items, etc) which players can possibly find and obtain through adventures, focusing on certain skills like instant death spells, etc. Another example is the Caloric Stone being a World Item among one of the hidden items discovered in the game. On the other hand, there are also apoithakarah, scarletite or other prismatic ores that were of the highest tiers in YGGDRASIL.

Defeated monsters tended to drop money easily. This was because there were many crafting classes in the game. Most of them made scrolls or wands and staves, which were frequently used by magic casters, and which they could use as well. If less money dropped, magic item production would become very difficult, and magic-using classes would have to think twice about going on adventures with intense combat. This went against the design philosophy of having players explore the world.

Furthermore, there does exist other functions (Forced System Access, Chat, Call GM, Log Out, and so on) used in the game. Normally, simply using the shout command or a GM call would put the player in touch with a GM at once shows how very capable that function was. An example of another function is the existence of a chat channel, where players can look to for finding recent news like the shutdown of YGGDRASIL. In addition to that, players can opened a system console and connected to the developers’ website to inspect the official guild rankings.

World and Dungeons
As it can be guessed from the title, YGGDRASIL mainly refers to Norse mythology, and has nine separate worlds based on it which are: Asgard, Álfheimr, Vanaheimr, Niðavellir, Midgard, Jötunheimr, Niflheim, Helheim and Múspellsheimr. While each world is a leaf of YGGDRASIL with their own particular traits, they were estimated to be two to three times the size of Tokyo. Other leaves were eaten by Navagraha the World Eater, or shed and transformed into World Items.

There were even nine huge guild bases of level 3,000, one for each world. If a weak guild were to control it, they would immediately be embroiled in complex guild wars, and holding on to the base would be very difficult.

Each of them was ridiculously huge, and there were many places within them which were difficult to explore. For instance, there were gigantic swamps, verdant expanses of rain forest, scorching deserts, and the like. One needed special equipment to delve into the dungeons there, as well as a proper strategy and the determination to throw one’s life away for the trip. This was because these hard-to-find dungeons contained monsters which dropped valuable data crystals.

In any world, be it either Niflheim, Helheim and Muspelheim — things became more dangerous the further one went from the center of the world. In addition to the wandering monsters, the very terrain itself became a hazard.

To add on, some dungeons could only be found under certain conditions. For example, the entrance to a dungeon amidst a field of flowers in the depths of a forest could only be seen under the light of the full moon. Additionally, there was also the Frozen City in Niflheim, which could only be entered during a blizzard.

The first time one ran a dungeon, there would be a bonus, or about 10% more treasure chests. Also, the first time a dungeon was cleared, the big treasure chest would offer equipment with item levels up to 10-20% higher than usual. Clearing the dungeon under certain conditions can even be awarding like being granted a World Item such as the Throne of Kings.

Moreover, Tabula Smaragdina stated that there are even dungeons with higher difficulty than let alone the Great Tomb of Nazarick. In particular, he seems to know one of those unnamed dungeons that needs 36-man parties (a legion) and allows two guilds to cooperate on invading them.

Dungeons ranged from different types such as a simultaneous attack dungeon like Nazarick. Many people hated simultaneous-attack dungeons, also known as “die-by yourself dungeons”. Dungeons like these required several parties working in unison along different routes to complete and were typically designed so that everyone would meet up at the boss room, whereupon they would face the raid boss together.

Level
In YGGDRASIL, the maximum level cap for a player can reach is 100. A player dying incurred two kinds of losses. The first was the loss of XP and a consequent loss of levels, though that depended on the way in which they were resurrected. This was not a big drawback in YGGDRASIL, because experience points could be regained easily, unlike in other games. Even if one’s levels went down for a while, the loss could be quickly recovered. In addition however, the death of a player character with level lower than 5 will only just revert them back to level 1 at the very least. The second kind of loss on the other hand, is the random dropping of an equipped item.

In other words, whenever a player character dies, it loses 5 levels and randomly drops one's equipment they had on. One could lose one or more pieces of equipment if a dungeon expedition happens to be very difficult. Because of that, people sometimes geared themselves up with second-rate items, the kind they would not mind losing. However, players could not clear the dungeon in one go with second-rate stuff, so they had to use their best equipment. The developers designed the game so that the most valuable gear would be dropped first, which meant that the chances of an important item which was key to the player’s strategy being dropped would greatly increased.

Nevertheless, this penalty can be reduced by using certain revival skills or cash items. When a player revives by skill, it can select the location he or she desires.Optionally, there were four different methods of resurrection to choose from in exchange for experience points. The first type was on-site resurrection. The second type was resurrection at the entrance of a dungeon. The third type was resurrecting at a nearby safe town. Finally, the fourth type was resurrection at a specified location, such as a guild. On the other hand, NPCs belonging to players or guilds can revive instantly by paying the right amount of gold and fee depending on its level.

In contrast to players, as monsters went up in level, they gained all sorts of special abilities. At this level, they could greatly decrease any damage done to them. While for NPCs created by players that die, they can be resurrected without losing any levels. However, it comes with the cost of using YGGDRASIL gold coins varied from different amounts, depending on the level of that NPC in particular.

In regards to leveling up as a player through killing others, the amount of experience points gained was reduced in accordance to the level difference between both parties, to a minimum of one point. Not to mention if a player's level goes down, the skills they've acquired at that level will also vanish and can no longer be usable.

Gold Coin Currency
The gold obtained in the DMMO-RPG called YGGDRASIL wasn't just used to buy items, it was also used for many other things for the game. One of those things included covering the administration fees for managing a Guild’s base-defense systems financially. In addition to that, it also includes the costs for automatically summoning servants of level 30 or higher, as well as a medium to launch certain spells. Moreover, gold is tend to be used to pay the manufacturing costs of items and even as a certain price for the revival of dead NPCs depending on their level.

Through using the creator tools sold separately, one could even customize the appearance of YGGDRASIL money and experience points in place of it's original setting. For example, say one have killed a dragon. Money and experience will still continue to drop by these said dragons as per normal DMMO-RPGs, but the way of modding the game only makes the image of them being dropped by monsters different. While the dropping of money and experience does not change, in place of these items visually however, crystals containing data are the ones that dropped instead.

Races
Races of YGGDRASIL can be roughly categorized into three taxa. There are more than 700 races, including racial classes that needs certain level of low rank racial class to learn. In the game, demihuman and heteromorphic races unlocked racial skills when they reached certain levels. Some items can change races permanently. In the game, humans and demi-humans, who had limited lifespan, would grow and age normally. In contrast to them, heteromorphic races with unlimited lifespan would stop growing after a certain stage.


 * Humanoid Races include human, elves, dwarves, etc. Humanoid races are weakest in basic status and cannot have racial level. Instead, they can learn more classes which provides high status or powerful skills more easily, giving them high potential. Adding familiar appearance to these advantages, human races were most popular in YGGDRASIL.


 * Demi-Human Races include orcs, ogres, lizardmen, etc. Demi-Human races can get more basic status and have racial level. Demi-Human races are similar to the average between Human races and Heteromorphic races. While the Demi-Human races weren't pretty visually, they can still performed better than Humanoid races.


 * Heteromorphic Races include slimes, vampires, devils, etc. Heteromorphic races own the most powerful basic status, which can be even more strengthened by increasing their racial level. High-rank races also provide special abilities similar to that of monster's. Beside providing racial level and special abilities, the Heteromorphic races are able to also gain more ability points than neither Humanoid or Demi-Human races. However, they were penalized in other ways as the racial level comes at a cost where it limits the amount of job levels one can learn. Thus, Heteromorphic races were very unpopular for that reason. PKing a Heteromorphic player doesn't give any penalty whatsoever to the player that did it.

Classes
The class system is considered to be the fundamental element of character customization. Counting the advanced classes as well as the based one, there are more than 2,000 classes in YGGDRASIL to choose from among players.

Although 15 is the highest level reachable in a single class, there were some high-rank classes that seems to have lower level limits. Thus, it is actually possible for a player to own at least 7 or more classes by the time they hit the overall level cap of 100. If one ignores efficiency, it is also possible to get a hundred 1 level classes. Of course there are some 'optimized' class builds discovered by players. In other words, it was a system where it was impossible to have completely identical characters unless you intentionally made them so.

Additionally, experimenting with different classes was only possible by dying and losing levels. Even if it was easier to gain levels in this game as compared to other DMMOs, it was still a time-consuming process for most players. In fact, some powerful classes were unlocked by PKing heteromorphs were beneficial among players. In normal games, most people would spread the news of a newly-discovered class on walkthrough sites to share with others. However, games like YGGDRASIL put a very high premium on information.

Depending on the skills and abilities they possessed, players can picked up different pieces of additional information upon exploring a new area. For example, such classes like alchemists and herbalists, with their herbalogical skills, would be able to learn about the various herbs that they could harvest in the area.

Whereas if there was someone who is level 90 with a rogue class job or a character over level 80 with full specialization as a rogue, it was near impossible to open a locked box. In a way, a high level thief would be able to steal items from the box. Just because a rogue could, did not mean said rogue could just immobilize his opponents and rob them dry. The limit would have been one or two items per player.

There were also some classes in particular, which had the penalty of not being able to summon monsters whose karma values were too far different from their own. However, the fact that Ainz did not have such classes was why he is still somehow capable of summoning angels anyway through using a super-tier spell. Incidentally, the monsters summoned by those classes can only become stronger the more closer the monsters’ karma values were to their masters.

The warrior classes were limited by one's real-world reflexes, that restriction only came into play during duels between top-class warriors. For that reason, warriors need to have a good body in real life to perform well in-game. It was not a deciding factor during normal play. According to Touch Me, when in battle, one could instantly sense an opponent’s intentions, thus evading his or her attacks.

Not only that, but there happens to be classes with some actual stories behind them all. For instance, Cursed Knights had the backstory of being corrupted cleric-knights who had been cursed for unknown reasons that aren't clear yet. Particularly, very strong classes like Cursed Knights for example are bound to have weak points and penalties as their drawbacks to make the game more balanced.

Guild
A guild can conquer a dungeon and use the place as it's headquarters upon being granted ownership rights. However, guilds could be able to only own one dungeon at a time. If a guild wanted to claim another dungeon, they would need to relinquish their claim on their present one.

Also, there were guilds that conquered and used a city as their base in YGGDRASIL. It was a common occurrence for different guilds to lay siege to a city. Ainz stated that setting up a base in a city would make some of the areas hard to defend against. Further, players could collect tax in a city base.

While so, there were just under 800 guilds created within the game, consisting a type of guild's ranking system among them all. In addition, discovering a dungeon could affect the world ranking of a guild. On the other hand, YGGDRASIL have a clan system which differs from a guild system although the latter has both.

Guilds are also granted NPCs, so they can set up to protect its base. There are three categories to these NPCs being:


 * Spawn NPCs pop-up automatically from the dungeons. The monsters which automatically spawned under level 30 had maintenance costs, depending on their type. It was zero for undead, but living creatures, in particular large creatures, had maintenance costs which increased proportionally to the size of their bodies. In YGGDRASIL, one could place pop monsters within dungeons by paying the appropriate in-game or real-world currency. However, they would not come back to life after being destroyed, so they were more of a luxury to players.


 * Mercenary NPCs can be summoned by spending guild finances. In addition, the mercenary system that summoned creatures in exchange for YGGDRASIL currency did not allow for the summoning of Death Knights. One good thing about them was that it could allow a solo player to form a group, but their AI was not very good, and their combat ability was lower than even a poorly put-together character of the same level. Upon grouping with such NPCs, people who aren't good enough were hindered when running difficult dungeons.

Financially, a guild base which only popped large living creatures would rack up a ruinous maintenance bill. If a guild base’s innate income was not sufficient to cover those costs, the guild members would have to earn that money themselves. In addition, trap activation and monster summoning were expensive as well. Being attacked by an enemy guild could incur incalculable expenses for the defenders, and might even force them into bankruptcy.
 * Custom NPCs can be customized freely, with their power level depending of the level of the guild stronghold. The lowest-ranked guild headquarters provides 700 level to be shared between NPCs. This can be increased by upgrading to an higher-ranked dungeon, using cash, etc. Customization tools includes not only level, equipment, and appearance, but also AI too. Thus custom NPCs can be made and used as powerful guardians. Of course, a guild is totally free to customize it's NPCs just for decoration purpose.

Magic
More than 6,000 different spells exist in YGGDRASIL. A level 100 spell caster usually knows around 300 of them (3 x caster level in the Web Novel). Even basic functions such as message needs spells to use, so most of the spell casters have trouble managing all the spell they desire to have.

On the other hand, there are cash items that could actually increase that number by another 100, making it a grand total of 400 spells within their control. Whereas there were also bonus abilities like "Dark Wisdom" inherited from a race such as Overlord could grant the player of that kind up to 718 spells, which is largely twice the amount a player could learn at max 300.

Magic is divided into eleven tiers: From Tier 1 to 10 and exceeding pass it is Super-Tier Magic. Super-Tier Magic has miraculous power that is even compared to 10th-Tier Spell, but suffers from huge casting and cool down time, preventing the frequent use of it. Casting super-tier magic decreases the caster's defense while receiving a certain amount of damage cancels the casting.

As consoles are not only mandatory for the game, but in addition, to also access the players' spells within their arsenal. The hotkeys on the console, ranging through a selection of the numbers 1 to 10 represents the ranking of tier spells a player can choose from and used in varying numbers. Players can arranged these spells via hotkeys in an order which Momonga for example, had forced himself to memorize. The player can also tap other hotkeys if one was planning to apply some sort of metamagic enhancements to their spells.

As the player cast their spell, an arcane eye or a magic sensor would then appeared in front of them. Afterwards, the player can manipulate that sensor by sending their spell towards a specific location of their choosing to initiate its power or effect. The player's right hand held the control stick for the sensor’s movements, while their left hand directs the sensor’s field of view.

Nevertheless, a player could hotkey up to about 480 spells in total. The ability to skillfully navigate these menus means fully understanding and memorizing the effects and proper application of each spell. It was considered to be one of the biggest factors in one’s ability as a Magic Caster. Just as warriors were affected by their real-life reflexes, magic-using classes relied heavily on their memory. A magic caster’s strength is measured by the number of spells they knows.

Parties
Parties were mainly made up of six players in total, and a dungeon raid could have a maximum of 5 parties only. In other words, the maximum size of dungeon raid consisted with 30 people in total overall when taking on bosses. Apart from exceptional cases like guild battles or fighting a World-class enemy, people who were over the limit would be subjected to friendly fire. If there were joke characters with a dream build among them, it would reduce the amount of fighting power they could bring to bear.

On the other hand, the party is categorized under Magical Attackers, Physical Attackers, Tanks, Healers, Seekers and Others were assigned to their parties. The "Other" category is viewed as those with challenging classes who were able to adapt to many different circumstances in any situation are players such as Momonga.

Nevertheless, the basic 6-man party configuration in Yggdrasil was one tank, two attackers, one healer, one seeker and a wildcard, who was capable of adapting to changing situations. Anyone taking on this task needed to be intimately familiar with everyone’s abilities and preferences. A team that was put together sloppily would not be able to succeed. Therefore, assigning party rosters was one of the greatest challenges of such an endeavor.

In addition, the sentries is formed as a party which would be used to stand guard at the dungeon entrance. Thus, they tend to keep a close eye out for anyone approaching the entrance. Depending on the circumstances, they were willing to go so far as to eliminate any interlopers.

In many games, one could not reorganize a party outside of a safe zone, or certain designated locations. In YGGDRASIL on the other hand, one could instead freely change one’s party anywhere and anytime. This allowed for very flexible parties, and with a good team, one could overcome any difficulty. By doing so however, the effects of party-wide magic and skills terminated once the party was disbanded. One had to take that drawback into consideration when regrouping. That trick would not work if used in a dire situation.

PVP
Otherwise known as Player vs. Player. According to Momonga, the most crucial thing in PVP is to deceive one's enemy such as Shalltear Bloodfallen. For instance, pretending that one player is vulnerable to holy-elemental attacks when they're largely immune to them after swapping out their gear. On the other hand, there’s the fact that they're still weak against fire-elemental attacks.

As well as PVP being the usual tactic used by a group of human players in order to hunt down heteromorphic players. Doing so will also be label as PKing which is player killing. There exists the contents of "PKing for Dummies" in which Momonga has spoken of before. Furthermore, there is also no penalty for PKing heteromorphic species existing in the game.

According to Punitto Moe, “Squashing” was his way of naming another PK method that involved attacking a player group that had just began delving into a dungeon from behind. Once their opponents were forced deeper into the dungeon, they would have to deal with the dungeons’ monsters as well as the PKs attacking them from behind. This was a kind of pincer movement.

Furthermore, Momonga even stated during his battle with Gazef Stronoff that having a weapon which is capable of killing someone is the absolute minimum condition for a solo PVP duel. In other scenarios, there was also a type of No-Loot PVP or the latter that he knows exist in YGGDRASIL.

By the way, some players would prepare a set of identical looking gear, equipped with completely different data crystals. In PVP matches, small tricks like that improved the players' chances of victory against their opponent. Although backup gear was typically weaker than one’s main panoply, being able to surprise a foe had effects beyond mere data values.

There is a limited cooldown period to players casting the number of spells from Super-Tier Magic. In addition, this cooldown period could not be eliminated by any skill or cash item. Thus, when PVPing, the party which cast a super-tier spell first was often considered an idiot. After all, defeat was likely the outcome any player will face when they expended their own trump card without properly understanding one’s foe. The fact was that there were very few PVP battles where the victors were the first to cast super-tier spells.

On the other hand, strong fighters in PVP matches have the tendency to be very popular with the spectators. While at the same time however, the voices of the supporters would slowly turn toward the challenger if they did well. In other words, if a player fought well against their opponent, more and more people would start to support that person.

Items
Items are classified accordingly to the following rank system: Items are drop as a data crystal from monsters, and players can produce items freely in the capacity of crystals, including options to customize their appearance and name. As a result, these data crystals could be slotted into almost any sort of item (apart from certain expendable items), in order to create just about any item a player could think of. In addition, there were certain artifacts which could not be created by players and had fixed stats. For instance, Horn of the Goblin General were examples of them.
 * Low → Middle → High → Top → Legacy → Relic → Legendary → Divine
 * Artifacts are not in anyways related to specific ranks. It just means they are items with fixed data. Therefore, artifacts with low rank can also exist.

Clearing a dungeon often yielded a variety of items, from rare data crystals to artifacts. In order to make one such as weapons and armor, it is through inserting a data crystal into an item skin. While magic items in YGGDRASIL were made by infusing an item skin with a data crystal, it was actually quite difficult to coordinate their appearance for players. After a certain update by the game's developers, players were given several ways to change their equipment's appearance without changing their gear that had stat boosts in it.

Players could design their equipment as they liked. Additionally, this included their powers as well. Player-made items in YGGDRASIL could also have their abilities be changed up by using data crystals. Yet the same way may even applied to the equipment used by NPCs like Narberal that had a quick-change crystal embedded in it and used for battle. That way, they would be able to directly swap out their gear for a set of predetermined equipment without having to waste time changing.

YGGDRASIL's equipment was classified according to how much data each item possessed. Items with more data were ranked higher. However, abilities could not be stacked randomly; the capacity of an item for data was determined by the item's construction and the material. In contrast, special effects took up a smaller amount of data capacity, so it was not uncommon for them to be imbued in an item to use up the leftover capacity. For that reason, not all data crystals dropped by monsters were equal. If one wanted to make a divine-class item, one would need several data crystals which were classified as "high-rare drops".

As expected, when comparing a sword made of clear crystal and a sword comprised wholly of iron, the amount of data needed for the exterior is completely different. The amount of data is determined by the resources of the item, such as minerals. So the goal was not only to destroy monsters, but also to search for resources and to explore for new discoveries. Players enjoyed calling themselves adventurers to do such things.

Theoretically speaking, one could create the ultimate weapon by embedding damage-increasing data crystals into a big weapon with high data capacity. Yet weapons like that were unwieldy, and would result in fewer attacks due to the difficulty of using them. Thus, the wielder's overall DPS (damage per second) would go down. It was quite common to require weapons made of special materials or with the appropriate elements to bypass monsters' abilities. The smith was also a key part of the equation. In YGGDRASIL, the humanoids called Dwarves had bonuses to craftsman-type classes to craft these weapons.

In YGGDRASIL, trading in magic items was usually done in the form of data crystals. However, there were people who sold second-hand items in order to make even stronger ones. It was at this point that a problem arose — the names of magic items made by other people might include forbidden language, or it might insult someone. Sometimes, the GMs would ask the players in question to rename the items. Most players named their equipment in reference to legends and mythologies, in order to make them an easier profit to sell. There were also cash items, which could rename them as it wasn't expensive.

On the other hand, there are World Items, whose power overrides the limit of other items. Many of them can ignore or even change the game system of YGGDRASIL.

Monsters
There were very few monsters in YGGDRASIL with attacks that were vastly different from what their appearances suggested. However, there were many enemies whose moves could not be predicted are a special case. Most monsters were generated by the same rules used for generating player characters. Even the magic they used was the same. The values derived from their basic stats such as health were also of a similar nature.

There were spellcasting monsters in YGGDRASIL. While the numbers of spells they could use varied greatly according to their level and species, as a rough guideline, they could use about eight kinds of magic.

In addition, the dungeons have bosses with different abilities, appearances, and boss rooms. Boss battles typically took place in a separate map, and there were some boss battles which allowed players to retreat from the fight.

The most powerful monsters in YGGDRASIL are called "World Class Enemy". Even Legion (6 parties with 6 players each) can have a hard time fighting against them. Moreover, being attacked by a World Class Enemy — an immensely powerful, hidden boss monster — had nearly destroyed a guild as a result of such encounter. Some of them are related to World Class Items. To the developers, the incredibly powerful last boss of the main campaign story-line known as the "World Eater" was the signature World-Class Enemy.

While so, there were at least about 32 level-breaking bosses in YGGDRASIL and some of them are listed below: In YGGDRASIL, there were two major patterns of raid bosses. The main problem with designing boss encounters was that the players had the same skills and spells that monsters did, but during raid boss encounters, there would be 30 players facing a single monster. Even if with enhanced stats, one monster would still be obliterated by sheer weight of numbers, which meant that there was no challenge at all.
 * Devourer of the Nine Worlds
 * Eight Dragons
 * Lords of the Seven Deadly Sins
 * Ten Great Angels of the Tree of Life
 * God of the 6th Day
 * Five Rainbow Buddhas
 * World Eater

As such, two main patterns of boss encounters appeared to address this issue. The first was to meet numbers with numbers. Sometimes the boss would come with minions, or the boss arena would constantly spawn monsters. In this approach, the boss was usually not very strong. In some cases, it would only have several times the health of a player character.

The other method was to send out a single boss, generated with different data from the player characters. This sort of boss typically had abilities which would give a lot of trouble to parties which encountered them for the first time, and it could use those abilities continuously. Judging by the look of the boss, it was highly likely that it fell into the latter category.

YGGDRASIL and the New World
Once every 100 years, players of YGGDRASIL are teleported without reason into the New World. It seems that the first teleportation had occurred 600 years ago. With the knowledge and exceptional power of YGGDRASIL, the players usually shake the very foundations of that world, making them legendary godlike figures to some of the native inhabitants' view.

Ainz Ooal Gown is currently the only known player to have been teleported to the New World, when he was expecting to be forcefully logged-out of the game during the shutdown of YGGDRASIL. From this moment forward, Ainz later decided to make an everlasting name for himself in the New World he is in now.

After arriving in this world, players like Ainz felt that some of the game's functions from YGGDRASIL has been removed and they cannot access its use anymore. For instance, there was no command console. Moreover, functions such as forced connections that did not require a console, the chat function, a GM call, a forced logout are no longer accessible in the New World.

Trivia

 * In Norse mythology, YGGDRASIL is the World Tree, a great ash tree located at the center of the universe and joining the Nine Worlds of Norse cosmology.
 * In YGGDRASIL, the advantageous world for heteromorphic players are Niflheim, Helheim and Muspelheim.
 * Creating a second character was forbidden in the DMMORPG, YGGDRASIL.
 * According to Touch Me, its quite possible that players can rent a guild base rather than conquering the dungeon properly to own one.
 * In YGGDRASIL, a blow to the neck counted as a critical hit and dealt extra damage.
 * A fatigue system existed in YGGDRASIL.
 * While players with their access to cash items could store much more in their inventories than NPCs do, even NPCs could still fit all of their equipment into their inventories.