Griefing
Originally, there were very few artificial restrictions on how players could interact, and the developers intentionally provided mechanisms for both attacking and stealing from other players. Most types of fraud and other indirect means for creating an advantage via the exploitation of other players were also not restricted, with the exception of when bugs were involved.
Some players saw a "punch in the nose factor" (as Raph Koster, AKA Designer Dragon, one of the original Ultima Online developers, put it) involved, as players were able to harm other players directly with little penalty, which allowed too much griefing. Others saw it as creating a more immersive and complex atmosphere where unpredictable and challenging situations could occur spontaneously between players, but expressed concern over the barrier to entry for new players and the seeming imbalance which favored anti-social behavior.
Gradual shifts in game mechanics and introductions of new systems took place. The developers initially added a system whereby the server categorizes criminals and murderers from the innocent in the form of differently shaded character and name highlighting (blue for innocent, gray for criminals, and red for murderers) on mouse-over. This, however, was not without its problems—many criminal acts could be accidentally performed while trying to do something otherwise legal, and the unfortunate player who suddenly became "gray" would most often be killed by NPCs or other players right away, regardless of the reason behind the criminal status. Players who killed others only because of their status and without regard for reason were often called "noto-PKs" since, at first, the notoriety statistic determined this status—these players, too, were often called griefers. Later, the developers altered an existing feature commonly known as "statloss" which decreased skills and stats. Before the change, upon death any player could opt to instantly resurrect with penalties, or become a ghost, whereby they must resurrect with a player or NPC with no associated penalties. The change caused any players who had reached "murderer" status to face these same penalties if they resurrected within a certain period of time after their offence - each offence added an additional period that the player must wait. Statloss was very controversial and was often cited as an example, by player killers and other PvP minded players, that the developers were siding with players who favoured the opposite style of gameplay. Eventually, the ongoing depredations of the 'red' community caused the creation of a separate, mirror world, called Trammel, where only mutually consented PvP and theft could occur, within or between player guilds that were in a state of war with each other.
Criticized as going too far in the opposite direction, some players cited the introduction as the downfall of the Ultima tradition of interesting and complex behavior, stating that the server-enforced laws were often too simplified to be appropriate in many situations and did more to harm the long-term health of the game world than it did to help it. Regardless, almost all player activity moved to Trammel, and the old world (given the name Felucca) became practically abandoned. Most subsequent MMOs have followed the example of Trammel, and do not allow unconsented PvP or theft (if there is a mechanism for theft at all).
In those subsequent MMOs that have allowed consented or nonconsented player combat, usually the items that may be taken from a player's corpse are limited (in some cases nothing may be taken). Ultima Online originally had no such distinction and all items a player had at the time of death stayed with the corpse, and every item was removable by anyone. This gave an incentive to griefing because it was more lucrative to kill and rob other players than a monster. An average troll may have yielded 200 or 300 gold. However, a player would often yield a full suit of armor, magic items, and consumables (e.g. potions, magic components, bandages, etc.) plus whatever gold he or she may have collected from fighting. As a result, the richest players and the most successful murderers were often one and the same. Successful player killers could make ten times robbing others than what they would fighting monsters. Those new to the game, who had played traditional computer RPGs, would often use the tactic of hoarding that worked in single player games, and would carry a majority of their possessions with them. When killed by another player, their murderer was richly rewarded and they were severely punished. Some new players quit in frustration when this would happen, as dozens or hundreds of hours of work could be invalidated in seconds with a prepared ambush.
Some still question the methods used to deal with the griefer issue. Raph Koster has said :
Being safe from evil is, in my mind, an uneven tradeoff for the fact that you don't get to be heroes anymore, in that you can just opt out of fighting evil. It may be nobody wants to be heroes except when it doesn't count, when it isn't challenging, that people would rather fight "pretend evil" than the real thing, but I don't personally believe that. I still think people are better than that.
Read more about this topic: Criticism Of Ultima Online