The Goals of Character Design
In many genres, games structure gameplay around characters. Action games (especially the fighting and platform subgenres), adventure games, action-adventure hybrids, and role-playing games all use characters extensively to entertain. Players need well-designed characters to identify with and care about—heroes to cheer and villains to boo. The best games also include complex characters who aren't heroes or villains but fall somewhere in between, characters designed to intrigue the player or make the player think. If characters aren't interesting or appealing, the game is less enjoyable.
Many factors combine to determine the degree to which a character appeals to people. A character need not be attractive in the conventional sense of being pleasant to look at, but he must be competently constructed—well drawn or well described. His various attributes should work together harmoniously; his body, clothing, voice, animations, facial expressions, and other characteristics should all join to express him and his role clearly to the player. (Disharmonious elements can be introduced for humor's sake, however, as with the cute but foul-mouthed squirrel
in the Conker series.) Characters should be distinctive rather than derivative. Even a stereotypical character should have something that sets him apart from others of the same type.
A good character should also be credible. Players come to know a character through her appearance and actions, and if that character then does something at odds with her apparent persona, players won't believe it. An evil demon from the underworld can't be seen worrying about orphans. For that matter, neither can James Bond. Simple characters must be consistent. Richer characters, with more human frailties, may be more inconsistent, but even so, players must feel that the character holds certain core values that she will not violate.
Important business considerations enter into character design as well. Customers identify many games by their key characters; that's why so many games take their name directly from their characters, from Pac-Man to the latest in the Ratchet & Clank series. Good characters occupy what the marketing people call mindshare, consumer awareness of a product or brand. You can use the character in a book, movie, or TV series; you can sell clothes and toys based on a character; you can use a character to advertise other products. It's more difficult to license a game's world or its gameplay than its characters.
The goal of character design, then, is to create characters that people find appealing (even if the character is a villain, like Darth Vader), that people can believe in, and that the player can identify with (particularly in the case of avatar characters). If possible, the character should do these things well enough, and be distinctive enough, to be highly memorable to the players.