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, serviced from 2126 AD to 2138 AD.

Introduction
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. Players can select numerous races and jobs and various tools allowing for customization. If you used creator tools that were sold separately, you were able to alter appearances of weapons and armor, interior data, character visuals, and detailed settings of a player’s home. It seems that the customization system is really far-reaching, even extending to basic programming.

Incidentally, in YGGDRASIL, one could equip magic items in the following slots: head, face, body, three pieces of jewellery 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.

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.

However, YGGDRASIL was a game where information itself had value. Like the case with World Class items, the number of people who freely shared newly discovered information with others was small. This was especially the case with classes that had a secret weapon such as Eclipse.

In the game YGGDRASIL, 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.

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. An example of this function is the existence of a chat channel, where players can look to for finding recent news like the shutdown of YGGDRASIL.

World
As it can be guessed from the title, YGGDRASIL mainly refers to Norse mythology, and has nine separate worlds based on it: Asgard, Álfheimr, Vanaheimr, Niðavellir, Midgard, Jötunheimr, Niflheim, Helheim and Múspellsheimr. Each world is a leaf of Yggdrasil. Other leaves were eaten by Navagraha the World Eater, or shed and transformed into World Items.

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 rainforest, 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.

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.

There were 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.

Level
In YGGDRASIL, the maximum level cap for a player can reach is 100. When 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 depending on how very difficult the dungeon expedition was. The developers designed the game so that the most valuable gear would be dropped first, which meant that the chances of an item which was key to the player’s strategy being dropped would greatly increased.

However, the death of a character with level lower than 5 will just revert the player back to level 1. This was not a big drawback, 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.

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.

Races
Races of YGGDRASIL can be roughly categorized into three taxa. There are more than 700 races, including racial class that needs certain level of low rank racial class to learn. 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.
 * Human Races include human, elves, dwarves, etc. Human 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.
 * Heteromorphic Races include slimes, vampires, devils, etc. Heteromorphic races own most powerful basic status, which can be even more strengthened by increasing their racial level. High-rank races also provide special ability similar to that of monster's. Yet Heteromorphic races were very unpopular, as the racial level limits job level one can learn, and PK on Heteromorphic races doesn't give any penalty to the player who killed Heteromorphic race player.

Classes
More than 2,000 classes exist in YGGDRASIL. Basically, 15 is the highest level reachable in a single class, yet some high-rank classes seems to have lower level limits. Thus, a 100 level player owns at least 7 classes. 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.

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.

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.

The warrior classes were limited by one's real-world reflexes, that restriction only came into play during duels between top-class warriors. It was not a deciding factor during normal play.

Guild
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.

There were guilds that also 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 are also a little over 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.

Guild is also granted NPCs they can set up to protect its base. There are three categories to these NPCs being: 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.
 * 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.
 * 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.
 * 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. 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. Even cash items could only increase that number by another 100.

Magic is divided into eleven ranks: From Rank 1 to 10 and exceeding pass it is Overrank Magic. Overrank magic has miraculous power that is even compared to 10th rank Magic, but suffers from huge casting and cool down time, preventing the frequent use of it. Casting overrank 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 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. 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 challenging classes who could adapt to many different circumstances are players like Momonga. One could freely change one’s party anywhere and anytime. However, the effects of party-wide magic and skills terminated once the party was disbanded.

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. 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.

In order to make one such as weapons and armor, it is through inserting a data crystal into an item skin. Clearing a dungeon often yielded a variety of items, from rare data crystals to artifacts.

Players could design their equipment as they liked. This included their powers as well. 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.

Theoretically speaking, one could create the ultimate weapon by embedding damage-increasing data crystals into a big weapon with high data capacity. However, weapons like that were unwieldy, and would result in fewer attacks due to the difficulty of using them. As a result, 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. Most players named their equipment in reference to legends and mythologies, in order to make them an easier profit to sell.

On the other hand, there are World Class 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.

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. Some of them are related to World Class Items. There were about 32 level-breaking bosses and 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
 * Seven Demon Kings of Sin
 * Ten Great Angels of the Tree of Life
 * God of the 6th Day
 * Five Rainbow Buddhas

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 he cannot access its use anymore.

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.
 * Normally, YGGDRASIL dungeons were not the sort that told you what levels were suitable for them.
 * According to Momonga, one thing that the developers of YGGDRASIL have forgotten was to make the game user-friendly for people who played it.
 * Creating a second character was forbidden in the DMMORPG, YGGDRASIL.
 * Most players thought poorly of the Yggdrasil developers.
 * According to Touch Me, its quite possible that players can rent a guild base rather than conquering the dungeon properly to own one.