Overpower

[Jason Yan]

In roleplaying, this means that a player uses cheap tricks in order to win a battle. It is Known as OP for short and is used by many anime roleplayers who takes the role of Saint Seiya, Dragon Ball Z (hence the facts that saiyajin could destroy mountains and cities with a beam and saint seiya characters cant be hit twice by the same tech/spell/jutsu, for example) and most, hellsing and elfen lied based characters, and uses their 10th sense, vectors, and goes to a monster transformation to enter god mode in all around based battle RPGs.
Overpower acts include:

Stopping attacks or actions without a logical reason, just because the character did it in the manga/anime;

Constant use of cheap dodging (like utsusemi, the famous replacement by a wood log), force fields that last for absurd amounts of time, or impassable barriers that does not get weak, even if there are conditions that may decrease their effect;

Some vampire players that are unaffected by the sun without having a logical explanation for it;

Summonings of monsters that could overhelm an entire planet, like tiamat and cthulhu;

Naruto characters who portrait Uchihas to use sharigans tricks.

[Lanell]

Gain mastery, Unfair

[Sommer]

Defeat or overcome with superior strength.

[Hina Muqadas]

to defeat someone by having greater strength or power: