SAO Game Mechanics

# This is an explained list of the mechanics and features within the SAO universe as it pertains to the Band of Brothers series. Some of these mechanics have been modified as deemed necessary to the author. In this way, the story can be more interesting and innovative to the readers.
== Mechanics ==
# No pain. This is one of the supposed guarantees within SAO. If anything, this feature is the one good thing that makes the whole "death game" scenario bearable. Unfortunately, like all video game systems, nothing is perfect. Pain can still be felt in a concept that the players named Phantom Pain. The frontliners were the first to experience the Phantom Pain and survive. There has been some rational explanations for this phenomenon, linking the pain to some sort of heavy ache. Sho has explained this effect as best as he could through neuroscience, but even he does not understand why the effects are so exasperated in certain situations.
# No blood. The closest thing to blood within SAO is the little orange flecks that are fly off when an attack lands along with the orange gashes that appear.
# No magic. There is no magic within SAO, or at least what can be defined as magic. The crystal system in the game is the closest form, allowing a player to teleport or heal himself. Energy-based moves like that of a dragon or other creatures do not fall under magic. Buffs and debuffs are also not considered magic.
# No long ranged weaponry. By long ranged weaponry, SAO specifically means bows and crossbows with any derivation of those items listed within the same class. Other ranged items still exist such as throwing knives, shurikens, boomerangs, etc.
# Sleep and hunger. Players still feel fatigue and hunger, even if their real bodies are not hungry. As a result, it is an absolute necessity for all players to eat and sleep within the game. However, there is never a need to defecate or go to the bathroom.
# The Ethics button. Players found this button relatively early in their time within SAO. Most keep it on while some turn it off. What this button does is censor mature content such as smoking, revealing body parts, sexual intercourse, etc. With this option turned on, there will be a pixelated shield over those mature activities. This button also does not allow a player to take off their underwear either, blocking any attempts whether it is from the user or from an outside source. Not only that, any sexual advances and touching in any odd way will be blocked and a large warning will flash. If the warning is ignored, the offender will be pushed away by the system. Additionally, this button is rather hard to deactivate, having to go through an entire sequence to find it within a player's menu. Of course, there are always ways around things.
#Sword Skills. Within SAO, there is a system that utilizes Sword Skills, a program-assisted move that allows a player to perform much faster and more powerful than in real life. This is the main way players deal high amounts of damage. Sword skills themselves have a hit limit per skill and the player will perform the entirety of the skill from start to finish without stopping. Skills can only be cancelled by dropping the associated weapon. All skills follow a specific set of moves that can be aimed in different directions.
# Normal attacks. Normal attacks performed by players are generally weaker than Sword Skills. This does not mean that normal attacks cannot kill a mob or another player. In fact, most PK kills are performed by normal attacks since this allows for more complex attack patterns.
# Outside system skills. These skills are dubbed as those that a player creates or utilizes without the aid of the system. The most common OSS is the "Switching" skill that players invented to confuse mobs. Other skills include those learned outside in the real world like martial arts or tracking.
# Crystals. Crystals are little rectangular blocks with special abilities. They can heal people's health, cure statuses and teleport people. Higher and more advanced teleport crystals can generate portals but those are highly expensive and rare.
# Immortal Objects & Durability. Durability is like the HP or life of an object. It is defined as how long an item will last before shattering and disappearing forever. Clothes, equipment, weapons, potions, crystals, and food are all subject to gradual loss of durability. Immortal Objects are those things that cannot be broken. These include physical surroundings such as walls, buildings, monuments, and major features. An error beep and a notification will sound if an immortal physical object is struck, even if by accident.
# Death. Death or deletion in the game is visualized by fragmentation into thousands of polygon shards. All monsters, items, and players that have their HP or durability reduced to zero, disappear and fragment into polygons in such a fashion. Player death in-game is also equivalent to death in the real world.
# Safe Zones and Towns. In town or a designated safe zone, a player cannot have his/her health reduced. Attacking a player in a safe zone will not decrease HP, but the recoil and impact of Sword Skills can be felt. This in turn can result in a player being knocked out with enough force. This also means that poison or other status effects like damage over time cannot be applied. However, the Phantom Pain phenomenon can still occur.
# Duels. Duels within SAO come in three types: First Strike, Half Health or Full Health. If done within a safe zone or town, the safety feature will be lifted for the duration of the fight. Most duels are in the first two modes for Full Health means to the death. Even Half Health is not used that much for a critical strike can send someone into red or maybe into death. That of course is akin to murder. It takes 60 seconds for a duel to start.
# Player Killing (PK). This is the act of killing or attempting to kill another player. Those who perform this are dubbed as PKers, hated murderers within Aincrad. Players who had repeatedly killed others in SAO were labeled as red players by the community. PK guilds were labeled as red guilds to distinguish them from 'normal' criminal orange players and guilds. However, if a person attacks anyone who already had an orange cursor, the former player's own cursor won't change, since the game interprets it as defending someone or protecting themselves. Known PK guilds are the Titan's Hand, or, more notably, the notorious red guild, Laughing Coffin.
# Color Cursor. A cursor interface can be seen over every NPC, monster, and player in the game. This cursor is green (for players), orange (for players with criminal infractions), yellow (for NPCs), or red (monsters). Crimes such as stealing (without a proper skill), hurting, and killing green players will temporarily turn the «Color Cursor» orange. Cursor color automatically restores over time for the first three crimes committed. The fourth time requires a player to complete a quest. Committing crimes five times will permanently make a player orange. PKers usually have permanent orange cursor color. Though the "red" term was coined, a red cursor is only for monsters. 
# Sleep PK. This is the act of sending a Full Health duel invite to a sleeping player. By manipulating their finger, a PKer can accept the duel, wait for the timer to tick down before killing the player in their sleep. This is seen as the only method to kill a player inside a safe zone.
# Suicide. Suicides can come in many different forms in SAO. Things such as running straight at mobs, at the boss or poisoning oneself count as suicide. However, the most common form at the beginning of the game was jumping off the world. Since there are no barriers on the edge of some maps, players can jump off the railing that is there. After two minutes, the system registers suicide and the player is deleted from the game.
# Broken or lost limbs. In SAO, a status known as "Broken Limb" or "Lost Limb" results from attacks to that specific area. When this happens, the visual effect of breaking a limb will be shown, most often with that body part looking out of shape or dislocated. Unless healed through a skill or crystal, broken body parts take around ten minutes to regenerate. Lost limbs take around a half hour to an hour depending on how much was lost. Even if using a potion, the limb will still take time to come back, albeit at a faster rate.
# Buffs and Debuffs. SAO features many different buffs and debuffs that can occur. Buffs positively boost the stats of players. Debuffs are statuses that can hinder a player. Things such as Dazed, Unbalance and others constitute to these debuffs. Paralysis and poison are under that as well. Debuffs can be cured by potions, crystals, or waiting out the effect.
# Guilds. Guilds are groups of players formed into an organization. Guilds get many powerful options towards customization; the main one being their very own base. Guilds usually decide on what to do in Aincrad, most taking up the mantle of frontline clearing. 
# Jail. In SAO, jails exist as ways to control orange players. The main jail is Black Iron, a building under control of the Aincrad Liberation Army. If a player is teleported there, they are locked up inside a cell that is not able to be broken, no matter the strength. The system strips them of their weapons and armor, replacing it with a prison suit. The collected items are stored within Black Iron's armory. The option is also there for locking up a player in chains. A set of specific keys are the only way to unlock cell doors and bonds. Security is said to be extremely tight around the prison with each meal shift carefully carried out to a strict protocol. However, rumor floats about that some prisoners are never fed. Breaking from jail is nigh on impossible especially during stressful conditions. Of course, nothing is ever a guarantee.
# Drowning. It is possible to drown within SAO when outside of a safe zone. After a certain amount of time underwater, a player will begin to lose oxygen and his/her HP will begin to deplete. Once all of a player's air is lost, even when HP remains, the player has only a few seconds before becoming registered as drowning. When that occurs, the player will be deleted from the system and death will occur. In safe zones, oxygen loss still occurs but players will not be able to die.
# Town Guards. Just like other MMORPGs, NPC town guards are highly powerful elites. Town guards are highly effective in the morning and days, able to detect and sense through the strongest of hiding skills. They only target those with orange cursors and are stationed at the entrances of towns, up on rooftops, and near the different places where portals are located. Guards will also respond to the sound of conflict if they sense that an orange player is involved. At night, guards are much less active. Following what would appear to be a real schedule of sleep and rest, guards will have shifts and will also reduce their numbers. This is usually the time when PKers or criminals enter town due to the relaxed defenses. However, do not be fooled. Although their detection abilities are lowered, a single guard can rouse his comrades who will come to his aid. This renders towns relative safe havens even during the night.
# Friends List and Guild List. After having friended someone, or if someone is in the same guild, another user can click on their listed name to do several things. They can check the player's location. This will reveal what floor the person is on. If they are on the same floor, specific location will appear on their map. This will not occur if the player is in a dungeon Players can also be messaged anywhere in Aincrad except in dungeons. A player can check their friend's health status as well, once again not available if they are inside a dungeon. 
# Skill Slots. Skill slots are the different sets of abilities that give players their power within a game. They fall under three categories: Non-Combat, Passive, and Combat. Non-Combat skills include action such as crafting, collecting items, and making food. Passive skills boost a player's natural abilities. Combat skills give players their sword skills and buffs. At floor 75, a player can only have 12 slots. Slots can be trained by repeating the moves or actions within that slot. Once a slot reaches 1000/1000, it is considered mastered. If a slot is dropped or deleted, a new slot will have to retrained from scratch.
# Item Rarity. Like most MMORPGs, SAO features a hierarchy of stats for items and materials. Items correspond to either Common, Uncommon, Rare, Ultra Rare, or Legendary. Common and Uncommon items are the usual average or above average items. They drop from any old mob. Rares come from Elite Mobs. Ultra Rares come from Mini-Bosses and Legendary items come from regular Bosses and Floor Bosses. The higher the rank of items the more powerful the stats.