Entry found in "Martok's Authoritative (Yet Completely Unoffical) Dictionary for Gamers".....
First Entry: MOO3
Function: noun
Etymology: (acronym) --> Master Of Orion [Three]
1.) The third (3rd) installment of the popular (but now tarnished) "Master of Orion" space strategy game series.
2.) A complete, massive disappointment of such epic proportions that psychologically and emotionally it is almost overwhelming. [context: "Last night's date with the two supermodels was a real MOO3."] (see also: "letdown", "snafu")
Second Entry: MOO3
Function: verb
Etymology: (acronym) --> Master Of Orion [Three]
1.) To completely bungle an item or situation that was previously thought to be nearly impossible to screw up. [context: "All you had to do to hit that stupid Orc was roll higher than a 2; you really MOO3'ed that one!"] (see also: "dropped the ball", "fubar")