The aftermath of a night of playing sci-fi role playing game Mass Effect or Mass Effect 2 for the Xbox or PC. This is usually the result of playing more than 4 hours at a time or playing until the sun rises. Symptoms include falling asleep at work or just being disoriented throughout the day. Can alter sleep patterns and cause slurred speech. If this pattern of late night gaming persists it could lead to altered perceptions of reality where you want to make decisions like Commander Shepherd or make constant references to the game in conversations with people who have no idea what you are talking about.
Example 1
Guy1: Hey man I tried to call you around 2pm why didn't you answer?
Guy2: Oh sorry I was suffering from Mass Effect effect and was still sleeping

Example 2
Guy1:Hey where were you last night?
Guy2:Oh sorry I was out with a friend you don't know
Guy1: (grabbing his shirt and slamming guy2 against the wall) Why don't you stop jerking me around and give me some answers
Guy2: Whoa relax "Commander Shepherd" I think you're suffering from the Mass Effect effect

Example 3
Guy1:Man my girlfriend thinks about sex more than most guys do, I swear she's part Asari!
Guy2:What the hell is an Asari?
Guy1:Or sorry man, I'm suffering from Mass Effect effect
by Changus Kahn February 2, 2010
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When someone discusses an amazing game around you, giving you the urge to play said game
Pete: Oh I always play as Male Shepard in Mass effect. So I can bone Tali.

Sam: aw shit. Now I’ve got the Mass Effect effect.
by Pogoextreme June 13, 2018
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