Hard-core gamers are much more inclined to like competition and direct conflict than are casual gamers. Part of this is because casual gamers tend to like short experiences while most games that have direct conflict are longer games, which allows that conflict to “play out”. Another might be that hard-core gamers are satisfied with or even crave the tension that comes from direct conflict while casual gamers are more likely to be trying to relax and are not looking for a lot of tension. Another reason might be that hard-core gamers are more willing to accept the frustration of direct opposition, of having obstacles that take some doing to overcome, as opposed to the casual gamers who want to see things happen in a game but not interested in being opposed. (Think of popular casual video games like Bejeweled and Tetris. There's only randomness, not opposition.)
Let’s differentiate between competition in general, and direct competition/conflict. You can compete in a contest where you never actually can affect the other player, you're just comparing results. Typing for five minutes and declaring the winner to be the person who typed the most correct words is a contest, and can be seen as a form of competition but is not a conflict. Hard-core video gamers often compete via contests, comparing their scores in various games or how long it took to "beat the game" as they play the same game but do not play each other: for example "I scored 17,000 in Tetris and you only scored 15,000 so I beat you" even though the players played solo because that's the nature of the game.
Wargames are almost always direct conflict, it's the nature of warfare. So people who are in the "wargames ghetto" as I've called it since I came back into the hobby eight or nine years ago, the ones who play lots of hex-and-counter wargames, are inevitably in conflict when they play one another. But SPI used to say many years ago that 50% of their games were played solo, and I think that's probably still true, that people play the wargames solo in order to experience (and experiment with) the history rather than for the conflict itself.
Wargames generally involve organized groups, usually governments, fighting each other either in short-term battle or long-term war. What kind of direct competition can we have that doesn't involve warfare? Business competition can often involve direct conflict, economic competition can certainly involve direct conflict, and individual competition can involve direct conflict. For example role-playing games are not about warfare usually but are direct conflicts. The big difference there is that they are cooperative games because one side of the conflict, the bad guys, the monsters, is controlled by a more or less neutral referee. In that respect they're like single-player video games except that a human referee can always be much more inventive than any computer program at this point in history. But in the video game world, especially MMOs, what has the trappings of an RPG can become direct conflict via the “PvP” (player versus player) mode of the game.
So we can have games that involve direct conflict but are not wargames per se. Sometimes that direct conflict involves violence (as in the MMO), sometimes not (as in the economic or business game). Sometimes these are what I call “screwage games”. These games for from three to many players are usually directly competitive but do not require a lot of reasoning for success, games that involve a strong dose of chance as well as skill. The games are more colorful than serious. Players are not focused on winning, they are focused on having a good time messing with their friends. They can be played the strangers as long as it’s played within a social context, such as at a game club with lots of other people around. The narratives of these games, that is the accounts of what happens, can be quite interesting or amusing, but the games themselves are not complex. The narratives can amount to pretty good stories, sometimes. And there is usually a fair bit of variety/replayability.
People who are very focused on winning aren’t likely to enjoy any screwage game.
In most cases a screwage game is played by a group round a table, with hands of cards, and simple scoring. “Beer and pretzels” is another term that’s often used for this kind of game, although it also includes other kinds of games so I’ve decided to use a different term. You could say that screwage games are a subset of beer and pretzels games. Screwage games are not usually “Take That” games; though there certainly can be cards that have striking effects, it’s not usually the case that a single card can vault someone from a poor position/situation to a good one.
Player elimination seems to be acceptable in many well-known screwage games but it’s not at all desirable. How can you mess with your friends when you’ve been eliminated from the game?
Give a screwage game to strictly Eurostyle players and sometimes you’ll end up with bewildered looks, as the game is so different from the games with little or no direct conflict that they’re used to.
One of the most well-known screwage games, although one with a severe design flaw from the point of view of really good game players, is Munchkin. (And I'll admit here that I don't care for Munchkin because the humor is silly and wears off very rapidly.) The design flaw is that there is rampant leader bashing and when the game is played by people focused on winning it becomes constant leader bashing until everybody is near the goal and finally somebody breaks through. But Munchkin is a very, very successful game because most people who play screwage games are not focused on winning, they're focused on messing with their friends and having a good time with others, and they don’t worry about the flaw (or don’t even realize it’s there, rather like the long-distance ticket flaw in original Ticket to Ride).
Nuclear War is one of the very early screwage games. While it theoretically depicts warfare between countries, for all practical purposes it's warfare between individuals.
Bang! is another screwage game that has been very successful, including a knockoff Three Kingdoms game that is very popular in China. Bang! is about the old West, the conflict between the sheriff and possibly deputies and outlaws, and people are shooting each other, but it's not warfare per se. Bang! relies heavily on unknown roles - although the role of the sheriff is known - and also has a mechanism that involves the range of your weapons so that you cannot attack anyone you want any time. This contrasts with some of the leader bashing that we see so rampantly in Munchkin when there's a fight, because anybody can join in in Munchkin. Whenever you can always target the leader then you're likely to have rampant leader bashing, especially if it's obvious who the leader is. In Munchkin you know everyone’s level, and reaching the target level is how you win.
Should you contemplate design of a screwage game - I’ve designed several, as they go over quite well at the university game club, especially when the subject is something like pirates or zombies or surviving the apocalypse - then be sure to limit in some way the ability of a player to attack every other player. Otherwise you may end up with a game with a Munchkin-like flaw.