Powergamers will use any dirty cheat they can think of to win at all costs. Tactics such as hording power-ups and fragging n00bs to score some cheap wins are common tactics used by powergamers in online games. They also beg and plead to start the game with cheat codes or ultimate weapons to start the game. Powergamers also won't let n00bs join their team,party, or squad in fear that the n00b may make mistakes and ruin their win percentages.
Jim and Ralph are powergamers they try to start the game with the class 1 zillion sword of world destruction and will horde power ups whether they need them or not to make sure the other players don't get `em.
1: n. A person who plays tabletop RPGs and seeks to make the most powerful character possible, often in the form of assigning 'useless' stats such as 'charisma' very low values. Any advantage this player they can get, they are likely to take. It is not uncommon for such players to ask to start with rare items their character could or would not have obtained.
Powergamers are different from twinks in that a powergamer generally seeks to have the most powerful character without regard to the rules, while a twink seeks to manipulate the rules to gain a powerful character.
1: "God damn it ralph, you're such a powergamer, and NO, you can't start the game with a Sword of World Destruction. No. No. No... Go away!"