A glitch (also known as a bug) is a fault in a program that causes it to function improperly. The severity of glitches can vary. Severe glitches include the infamous Falador Massacre, where a player was able to attack other players outside of a player-versus-player zone. This was an extraordinary case as most of the glitches have no impact on the gameplay, and neither are harmful to other players.
Rules on bug abuse
Abuse of glitches is a direct breach of the "bug abuse" rule as stated under Rule 4 of the rules of RuneScape. The punishment for guilty parties varies depending on the particular glitch and the degree to which it was abused. Minor graphical glitches generally go unpunished while major abuse may result in a permanent ban.
Jagex has recommended that players who find a glitch in RuneScape should report it to Jagex immediately via the "Submit a Bug Report" interface on the RuneScape website main page.
Noteworthy glitches
6 June 2006 Falador Massacre
The Falador Massacre was an infamous glitch where a player (Durial321) was able to attack other players after a glitch involving player-owned houses was discovered, and he proceeded to attack many players in the Falador area until he was stopped.
Noclip glitch
The noclip glitch allowed a pair of bug abusers to walk through barriers in RuneScape nearly entirely unrestricted.
Partyhat duplication glitch
The partyhat duplication glitch is one of the most famous glitches in RuneScape where a third-party program was used to manipulate the game engine, thus allowing the creation of items.
Bolt duplication glitch
The bolt duplication glitch was a glitch where the player could enchant multiple bolts out of only a single bolt, thus vastly multiplying their profit.
Equipable knife glitch
A glitch in RuneScape Classic allowed multiple knives to be equipped allowing massive damage to be dealt.
Guthix rest tea glitch
The Guthix rest tea glitch caused the drink to heal the player entirely, as well as remove poisoning, and restore run energy.
TzHaar massacre
The TzHaar Massacre was a glitch that allowed players in the waiting lobby of the Fight Pits minigame to be attacked causing them to lose their items on death.
Adding yourself to your friends list glitch
Several methods, including utilising display names and adding spaces before or after their name, allowed players to add themselves to their friend or ignore lists.
Player moderator forums glitch
A pair of bug abusers found access to the player moderator's forum through a security exploit.
Attacking players in the Tower of Life glitch
Upon release of the Tower of Life, the basement's placement directly below the Wilderness allowed players to attack each other.
In extremely rare cases, e.g. multiple players being able to kill each other outside of the Wilderness or mini-games, it might cause Jagex to do a complete shutdown of the game (which has happened in the past) making all worlds offline followed by banning the players who are using such a glitch.