It's not dark Speech, but it will help you not to be so lost when your in the presence Eliteness.

1H / 2H: one handed and two handed weapons.
Add / Adds: one or more monster or into the fight.
Aggro: is the invisible area sorrounding a monster where he will start attacking you. This varies depending on level and weapons.
Alt: another character from the same player. For example: I play a hunter, my alt is a minstrel.
AoE: Area of Effect. When a skill or item deals damage to an area and not to a single npc, monster or character. Example: fire.
BoA - Bind on Aquire
BoE: Bind on Equip. The item will be bound (you will be not able to sell it) once equipped.
BoP: Bind on Pick Up. the item will be bounded to you once you purchase it.
Buff: a temporary increase in one or more stats... for example by eating food or using a skill.
CC:Crowd Control, a set of skills that allow players (Lore-Masters specially) to deal with more than 2 mobs at a time easily.
Crit: critical chance or critical. Related to crafting or critical hits (chance to deal more damage with a skill)
DoT: Damage over time. An effect from a skill or item that deals damage through a period of time.
DPS: Damage Per Second. A way of measuring the damage from weapons.
Dread: a modifier to your stats. Generally decreases a percentage of your skills down.
Drop Rate: the frequency a mob drops an item.
Exploit: a flaw in the game that allows to cheat.
FM: Fellowship Maneuver, also called Conjunction.
Instance: a part of the game world that is private for a group or individual. Other players getting into the instance will have their own game experience separated from each other.
LFF: Looking for Fellowship. You are alone and you are looking for a group.
LFM: Looking for More. You already have a fellowship and you are asking for more to join.
Lore: the story and history of the game world.
MA: Main Assist. The person in a fellowship that assists (hits) mobs to defend and support other players... or Tank.
Mats: materials for crafting, often refered to how many items and money required to craft an item.
Melee: close combat.
Mezz: to stun or freeze or stop a mob for a moment.
Mitigation: the ability to absorb attacks
MH: Main Healer. Normally a Minstrel and secondary classes that can heal at certain levels like Captains and Lore-Masters.
Mob: an NPC monster or creature.
Named: a monster or creature that stands among others. Usually a signature that has his own name and its unique among its species. Example: Sargurz, Karnasht, Silverclaw.
Need / Greed: the action taken when looting in a group.
Noob, Newby, l33t, N00b: an inexperienced player.
NPC: Non Player Character. A computer controled character: vendors, monsters, etc.
OMW: On My Way
Power Levelling: the action of doing quests and spending virtual money to get to higher levels faster.
PST: Please Send Tell. to send a /tell (private question).
PUG: Pick Up Group, a casual group.
Pull: the action to hit a mob to start a fight.
PvE: Playr vs. Environment.
PvP - PvMP: Player vs Player, Player vs Monster Player.
Raid: a combo of 2 to 4 Fellowships.
Regen: the process to regain morale and power (or other stats).
Reset: the action when a mob or NPC returns to its original state.
Rez: from resurrect. The action to bring back a character from being defeated.
RP: Role Playing
Spawn: the moment where a mob appears.
Tank or MT: the character inside a Fellowship that is supposed to take aggro and absorb the hits while other players try to defeat him.
TS: TeamSpeak a chat server or service
Vendor: an NPC that sells stuff.
WTB: Want to Buy
WTS: Want to Sell
WTT: Want to Trade
XP: Experience Points.
Vent, Ventrilo: hat server or system

Very handy,thanx

BoA - Bind on Aquire

Maybe we can get one of the admins to add new words to the list so no one has to search a through a long list of posts, and clean up.

\/\/00+ - an expression of glee and joy - not to be confused by woot which is the noise an owl makes

Thanks for the list Maddux, stickying
I'll amend the original with any new acronyms.

Thanks for the list, there were a few I had no clue what they meant.

Alot of them are from EQ... or least was used in EQ but some are "LoTR Online" only

-RMS Carpathia-

What are guilds called in LOTRO?

Great list

Clans are called Kinships in LOTRO Nok.