In alphabetical order:
AC = Auto Combat (same as FC)
AFAIC = As Far As I'm Concerned
AFAIK = As Far As I Know
AFK = Away From Keyboard
AOKH = Age of Kings Heaven
AOMH = Age of Mythology Heaven
AOWH = Age of Wonders Heaven
AOW2H = duh
ASAP = As Soon As Possible
ATT = Attack (Increases the Unit`s chances of hitting Enemies with Melee Strikes)
BBL = Be Back Later
b/c = because
BRB = Be Right Back
BSOD = Blue Screen Of Death (the one you get when Windows crashes)
BTOOIC = 1. Buildable Teleporters Off Option In Cities
BTOOIC = 2. Bound To Outlive Other International Clans
BTW = By The Way
CMM = Custom Map Making
congrats = congratulations
DAM = Damage (The Unit`s maximum Damage each Melee Strike)
DEF = Defense (Increases the Unit`s chance of avoiding Physical attacks)
dev = Developer (from Triumph Studios)
DSH = Dungeon Seige Heaven
FC = Fast Combat (same as AC)
FMDS = Free Moving DragonShip
gn = goodnight
grats = congratulations
HP = Hit Points (The amount of Damage the Unit can take before being destroyed)
IIRC = If I Recall Correctly
IC = In Character (if you are roleplaying)
IMHO = 1. In My Honest Opinion
IMHO = 2. In My Humble Opinion
IMO = In My Opinion
KoRT = Knights of the Round Table (the main "outside discussions" forum at the HG Community Forums)
LMAO = Laughing My Ass Off
LOL = Laughing Out Loud
m8 = mate
MOM = Master of Magic (old TBS game)
MP = Move Points (Determines how far the Unit can Move each Turn)
n8 = goodnight
np = no problem
nt & n/t = no text
OMG = Oh My God!
OOC = Out Of Character (if you are roleplaying)
PBEM = Play By EMail
ppl = people
RES = Resistance (Increases the Unit`s chances of avoiding magical attacks)
RMG = Random Map Generator
RTG = Random Terrain Generator
RTS = Real Time Strategy
ROFL = Rolling On the Floor Laughing
ROFLMAO = Rolling On the Floor Laughing My Ass Off
sik, sikkie = developer "sikbok"
SM = AoW: Shadow Magic
SOL = S**t Out of Luck
TBS = Turn Based Strategy
TC = Tactical Combat
TIA = Thanks In Advance
TS = 1. Triumph Studios (the developer of the AoW games)
TS = 2. Triumph Studios Rules (the standard rule-set)
TS = 3. Turn Sent (in a PBEM turn log)
TVoW - The Valley of Wonders (the old AOWH "OD" forum)
ty = thank you
w/ = with
w/o = without
WL = Wizards Ladder
WR = Warlock's Rule-Set
YGM = You've Got Mail
yw = you're welcome