Sometimes, when people play games, their only goal is to win. Sometimes this results in using tactics such as extreme rulings. ("You didn't discard a card when you had 8 in your hand? That means you cheated! I win!") Giving bad advice to beginners. ("You don't want to buy as many properties as you can early on. You want to save up as much money as you can.") Being mean. ("What do you mean you're attacking my base after I bought you lunch earlier today, you backstabbing jerk!") Even blatant cheating. ("I hope no one figures out that I'm using trick dice.")
Before you try using any of these tactics, you might want to ask yourself a few questions. "Do I really want to win in a way that doesn't test my skills and give me a chance to improve them? Do I really want to win in a way that will push people away instead of building friendships? Is winning really worth sacrificing morals, friendships, and chances to improve my skills? Do I really value winning more than all of these things?"
In a roleplaying game, it's even more important that winning not be the only thing you care about. Sometimes, the other players will have put lots of hard work and creativity into their characters. Their characters might be special to them, and they might get upset if you decide to kill those characters just so you can take all of their stuff. Is the resulting sense of power really worth damaged friendships? Will it let you improve your skills and become more skilled than before? Will it even give you a better chance of success than having the other players' characters there to help you would? Take a moment to ask yourself what is important to you.