That One Player describes someone who has played a game so much, discovered all the secrets, knows all the moves, hell, he might as well have gotten the timing down to the point where he plays with almost super human reflexes. However, this ruins the fun of everyone else who plays with or against that one guy because he's so skilled, he's either doing all the fun parts or able to take on an army of adversaries without breaking a sweat. However, sometimes being That One Guy can be a talent for entertainment, when he can show off his inhuman skills.
That One Player, though, may not necessarily mean a stop having fun guy or the other way around. Nor is he That One Boss, though if he was a boss, he would be. May possibly be a Challenge Gamer, which would certainly explain their ungodly skill. And chances are they are a munchkin, and their munchkinry is to blame for their annoyingness.
Some video games have a "handicap" option to either make a certain player weaker or everyone else stronger, purely to keep That One Player from restricting other players' fun... or their own, for that matter.
Not to be confused with The One Guy, a trope about one male character in an otherwise all female cast.
- Konata Izumi of Lucky Star is seen playing a fighting game at an arcade in one episode. She beats a guy, much to his dismay of finding out who beat him. A strip similar in idea was: since she is excessively short, the other tomboy misjudged her ability and got owned. On the next day, that other tomboy beat Konata— but with such razor thin of a margin that she knew that Konata let her win!
- Ami Mizuno in Sailor Moon manages to be this on a game she has never played before, twice! First a platforming game in the original series and then a fighting game at a tournament in the Stars series. She's just that smart.
- Makoto Kousaka from Genshiken is like this with all video games, but his skill at fighting games (as well as Puyo Puyo) makes other otaku quake.
- In Ai Kora, Closet Geek Yukari is secretly a fan of video games, and likes to unwind after final exams by going to the local arcade incognito and getting a high score on all her favorite games under the alias "Fantazma".
- Sora and Shio in No Game No Life turn this Up to Eleven. Through teamwork, and years of experience from never leaving their house they are the greatest game players in the world to the point that they catch the God of Games' attention and win an invitation to his world where everything is based on games.
- White Devil of the Moon, a crossover between Nanoha and Sailor Moon, has Nanoha perform so well on the Sailor Moon arcade game that she maxes out her score and reaches a Kill Screen. She notes that the only thing difficult about it is that it was built for right-handed people (Nanoha is left-handed).
- Monster House has one of these, who gives the kids a vital clue as to how to handle the eponymous creature.
- How I Met Your Mother: Marshall Eriksen has a preternatural skill for board games, such that he can deduce the rules of a complex foreign gambling game just by watching others play for a few minutes, despite not understanding what the players are saying. His friends assigned him to officiate their game nights rather than playing, because otherwise he'd win every time.
- Nestov in Tracker was this with one of the video games in the Watchfire. He could analyze the math and patterns well as a Dessarian, according to Cole. He was making bets and money off it.
- The song "Pinball Wizard" by The Who is about a psychosomatically deaf, dumb, and blind kid who still manages to be That One Player.
- In Final Fantasy VII: The Sevening, Yuffie is apparently really good at fighting games.
- Exaggerated and parodied with AAA, who's essentially the best player in the cosmos.
God: Who's this guy who always beats my Pong high scores?
- Posters on 4chan's video game board sometimes post about their (fictional) encounters with the Memetic Badass player known only as "Gregor", who joins a server and proves to be frighteningly competent at whatever role he chooses to play: offense, healing, whatever, and somehow knows exactly how to coordinate with his teammates in every situation despite never using any voice or text chat.
- South Park: the main characters take up World of Warcraft, but find it unplayable because a griefer has leveled up so high that even the admins can't ban him. As you can see, IRL he's just a Perpetual Frowner fat guy.
"But how do you kill that which has no life?"
- A running gag in Aladdin: The Series was that Genie would always lose to Carpet in the many, many games they played.
- The concept behind Captain N: The Game Master is that they brought That One Player into the world of video games, so he could use his skill to help them fight villains.