As I've become more inclined recently to play short-burst competitive video games in recent days as opposed to the usual immersive 30+ hour epics, I've naturally been having a lot of thoughts about various aspects of that subset of games and wanted to share them somewhere public (mostly because my life is in the most vexing transitional period possible on top of the world going crazy over the past seven months and I just want to put some energy towards something that feels productive, like say starting an interesting discussion on a forum). I eventually settled on the topic of main characters in these types of games, what they are, why and how people choose them, and what impact they have on a player's enjoyment of a game. Also while I'm aware this concept applies to single-player and cooperative games to a degree, I'm mostly going to keep a focus on competitive environments since that is where mains are most important to the player base at large. Also get ready for a lot of fighting game examples because I'm biased.
So, What's A "Main Character?"
At the absolute most basic level, a "Main Character" by my definition is a playable character in a video game with asymmetric design that a player consciously chooses to devote most of their playtime to. A given player can have just one main, or main two or more if they put in the time to play multiple characters roughly evenly, though some games may be built to force a player to avoid lazer-focusing on one character. League of Legends and many other MOBA games for instance feature pick and ban systems which potentially limit the availability of a character one wants to play, encouraging players to learn multiple characters in case their star player is taken from them for one reason or another. The most important element of the definition is the asymmetric design, as while almost all competitive games have some form of character select screen, some of them feature characters that play with the exact same mechanics, meaning these mostly boil down to aesthetic choice. You're certainly free to claim a main in TowerFall, but its mostly an empty statement since picking Assassin Prince has no significant differences from playing Last of the Order or any other character.
Why Do Players Choose To "Main" Characters?
The most fundamental reason this practice started, from a competitive standpoint, is so that player can become intimately familiar with a single set of mechanics and utilize that mastery when competing against others. Many games with asymmetric design feature character select options so distinct from one another that learning to play any one of them well is a game within itself. A fighting game like Blazblue, which literally features a button that throws out attacks/mechanics wildly unique to each character called "Drive," demands such different executions from players based on character choice that achieving mastering just one or two characters buys a player a significant advantage over simply being good with many of them. It's the quality of the technique on display over the number of techniques known. Other games feature characters that handle fundamentally the same but alter statistics underlying their controls, such as in modern Mario Kart games where difference character and kart configurations affect top speed, acceleration rate, ect. In these cases, proficiency with multiple characters allows a player to adjust their strategy based on the situation much more easily, though having a hard main can allow players to develop a unique style of play based on their stat load-out (I for example play best in Mario Kart by maximizing top speed to put distance between me and opponents early in order to reduce the risk of getting caught in a frenzy of items).
How Do Players Select Which Characters to Play?
The question of how people select their main is one with a huge number of answers, but I'll cover as many as I can. The most immediate strategy is to choose a character which gives a player the best chance of winning. Asymmetric games are almost inevitably prone to having certain options be better than others, so a serious player may seek to master the options which a provably better that the others, or ones that are difficult to counter. Of course not every strategy will necessarily be comfortable for every player to utilize, so some will combine their desire to use provably powerful characters with their preference for another character, who is usually less powerful but they can push to the top with regardless since they enjoy them more or play them better. On the other end of the spectrum, some players seek to master characters regarded as weak in order to take advantage of other players' unfamiliarity with them, as most players spend time developing tactics to use against the common power picks. Finally a large category of reasons can be boiled down essentially to either fun factor or aesthetics. For the former, a player likely tried every option and landed on the most enjoyable one as their main in order to make their climb to the top as entertaining as possible. The later is likely a player who sees the character as an avatar of sorts, and wishes to let that character's thematic identity serve as a herald of their presence. Most people select a character for a combination of these reasons, perhaps wanting to play something both fun to play and has the low tier advantage, and more still may have other reasons for selecting a particular main.
What Effects Do Main Characters Have on the Play Experience?
Finally let's talk about the various ways that having mains affects players. Perhaps the most notable effect is that dedicating time to one main can affect one's play-style and their approach to a given genre as a whole. As a fighting game player I tend to chose characters first and foremost on aesthetics and what fantasy they give the player, and as such I've played everything from zoning to all-rounders to puppet characters for the sake of embodying a character. However the first character I ever took to seriously mastering was a rush-down character, and I've tended to develop aggressive variations on all of the previous play-styles. Soul Calibur's Siegfried may swing slow and heavy, and I compensate to a degree, but having learned to fight first as Blazblue's Noel Vermilion, my Siegfried play involves much more proactive pressuring than normal. Other players use this initial learning experience as a guide for what characters they should play through out their careers, with a fan of Street Fighter's Ryu perhaps choosing to seek out other well balanced fighters in other games like Arcana Heart's Heart Aino. Selecting a main can also have social implications as well. If a particular character becomes (in)famous for one reason or another, usually for being powerful, this may affect community perceptions of those who play them. An extreme example of this would be Super Smash Brothers for Wii U's Bayonetta, who was so powerful that people claimed those who did well with her were just carried by their character choice, a serious accusation at the highest level of play since wins are largely regarded as truly skill-based at that upper echelon.
On a more ordinary level, I think the greatest psychological effect of having a main to the wider community is that improving with that character becomes a palpable measure of the player's skill they enjoy tracking overtime. Whether it comes from improving with one character as high as you can, or getting good at a character you once thought impossible to play, there's a sense of achievement to staying loyal to a given play-style that for some is simply unmatched. On the flip-side though, hitting what seems to be a plateau can be frustrating for players and lower their enjoyment, and some simply get tired of sticking to one strategy. At the end of the day, its up to each individual to know themselves and what they want out of the game in order to have the most fun.
In conclusion, having main characters in the competitive gaming setting is a very important part of the culture, and is perhaps one of its defining features in the modern era. I hope you found something valuable out of this little exploration of a metagame concept, and if you have any questions or thoughts please feel free to let me know. I would love to hear what effects you think this piece of competitive games has on their general atmosphere in particular. Have a great August everyone!