Nowadays, in order to appease the audience, games become more and more diverse thus they need to constantly expand a pool of characters. However, the number doesn't always keep up with the quality, as for the single-player games like Uncharted, it doesn't require that much imagination to design the character's concept if the game is supposed to have a protagonist, antagonist and a few side characters.
But what if the game is supposed to contain hundreds of characters and each one of them should be distinctive enough to feel unique and vivid? Even such industry moguls like Dota 2 from Valve can't always physically keep producing original heroes after they have already surpassed a hundred characters threshold. For instance, let's peek last three heroes released in Dota 2: Monkey King, Pangolier, and Dark Willow. All of them represent little agile animals with the same body size and very similar animation. Part of the reason is catering to the Asian market whose players enjoy the local-themed appearance of the heroes.
Another premise comes from Source 2 engine not being able to create a multitude of unique model features and animations. The same issue applies to League of Legends from Riot Games - the game currently features more than 130 champions many of which only differ from each other on concept-art depictions and cinematic videos.
The sheer answer to making each hero unique is to reduce their number like Blizzard Entertainment often does. Having only 25 characters in Overwatch plus releasing short videos about their background allow for keeping the heroes different from one another and interesting for players. Each character has their own operative base country, real name, age, military forces allegiance. It is rather apparent that the developers have been inspired by various books, movies, and other games. For instance, McRee is very reminiscent of western genre movies' star Clint Eastwood, Angel is a Bible-related character, Torbjörn looks the same way as the Dwarves in another Blizzard Entertainment game, World of Warcraft.
Furthermore, another Blizzard game, Heroes of the Storm, was basically designed to borrow the characters from their own products. Not only this drastically reduces a chance of bad reception from players, as usually only the fan-favorites personas get added to the game, but it also nullifies all the possible copyright issues since the company owns all the character names and visuals.
Another good technique to adopt from Blizzard is designing the appearance and background of the characters by dividing them into races and classes. In World of Warcraft, each race has its own capital city and a very distinctive appearance that can also be diversified depending on character's gender. Special class sets and armor types with special colors and effects on their outfit, many of which have been borrowed from medieval times, also make every class look unique.
But what could be an infinite source for creating the characters? A simple way to create a design is to borrow it from the real people. For instance, Jean-Claude Van Damme is a prototype for Johnny Cage in Mortal Kombat, Gabe Newell is a boss in Crawl, Tony Hawk is a skater in the game of his name. In order to help you find an additional source of inspiration, let's sneak peek a little bit deeper into the topic.
Mythology is among the leading spheres that inspire the developers to create godlike characters. Dota 2 features Zeus and Hercules in a game of his name as well as Thor and Kratos as the main character in God of War.
Ancient mythology is an excellent source for charcters' look for action games, RPGs, and MMOs.
In World of Warcraft, you can meet Odyn as a prototype for Odin, Valkyries, borrowed from Norse mythology, and creatures from ancient Egypt. This is a great option for developers as the copyright tensions are highly unlikely to occur and the ancient mythology is often perceived as a fancy attribute rather than a sensitive topic.
Religious personas can also serve as the characters. Games like Diablo and DOOM couldn't exist without the Devil and the demons. Fight of Gods, on the other hand, features the characters from major religions across the globe. However, in case of using this option, the developers and their publishers should be ready to get a ton of mixed reactions as the religious topic may be controversial to a wide range of public.
Religious topics are quite popular, but you have to be careful while drawing too much inspiration for it in order to reduce possible criticism from the spiritual community.
For instance, Fight of Gods has been excluded from Steam’s shop by the Malaysian government, who claimed that the game had violated numerous religious laws. On the other hand, this example might spur to develop such games as the wrangling around it only raised an interest towards the product, despite the that wasn't a masterpiece by any means.
Events all across the world are a great addition to many games either since they can feature different characters such as vendors or entrepreneurs. Darkmoon Faire in Wow is a well-known event that takes place outside of the major cities and served as a platform for a real band Elite Tauren Chieftain made by the developers and to a whole multitude of TV show characters prototypes.
Incredible consumes, mind-blowing decorations painted in every color, and thousands of unique individuals what could be better than Brazilian carnival when searching for characters?
All the holiday celebrations also serve as a great platform for implementing the new outfit and a themed character, barely any game misses a chance to release pumpkin-related content prior to Halloween. Even such horrendous events like World Wars can serve as a rich well to gain a ton of spectacular characters to showcase their prowess or infamy.
Military Forces and their natural enemies, the terrorists, are also very often portrayed in first-person-shooters like Counter-Strike, Crossfire, Rainbow Six Siege, and many others. Various Counter-Strike iterations have featured real-life special group like FBI, GIGN, GSG-9, Spetsnaz, SWAT as well as a multitude of terrorist groups.
Counter-Strike, for example, mirrored the military outfit used by different special forces during various military operations.
Colorful insignias and a diverse dazzle paint on the uniform may serve as a tool to create racy characters. Even such abhorrent events as World Wars served as a premise for great games like Medal of Honor and Call of Duty. More contemporary events in Middle-East were also projected in Battlefield and Insurgency.
Animals are also among the most influential creatures when it comes to designing the characters. Roughly every contemporary game has a list of animal-like characters who don't usually serve as pets but can also perform human activities. Anthropomorphism is a necessity nowadays as we all want our character to be independent regardless of which hero type we are going to play: an anime-girl or a wolf-polyglot.
Pandarens from Warcraft, Sonic the hedgehog, Worms, AngryBirds, Crash Bandicoot, Donkey Kong, and many others, despite being released more than a decade ago, are still prominent in the gaming industry. Modern developers also don't hesitate to feature animals as the playable characters: every massively multiplayer game has a bunch of squirrels, wolves, wild cats, etc. available to the player.
Cute, sweet pandas became prototypes for one of WoW's martial nations.
Fantasy is one of the safest bets when it comes to character designing. Borrowing the content from fantasy books is fairly easy as it can be deviated towards any direction due to the core fantasy nature. A fictional hero can have any set of skills and can only be limited by the imagination of the author. The same rule applies to object's appearance: it doesn't need to be either rigorous or precise. The only limitation is the setting - a modern first-person shooter would look bizarre, if it would feature wizards, orcs, elves, and/or dragons.
Despite some of the cultures are long gone in the present day, the games can serve as a great platform to revitalize all the fancy ceremonies and outfits. Apart from the Egyptian culture mentioned above, we can take Roman Empire featured in Rome:Total War with its legionnaires, gladiators, centurions, and emperors as a prime example of portraying cultures when developing character concepts. But don’t be fooled by these two, there are many other great cultures to learn from such as Ancient Greeks, Maya, Babylonians, or Ancient China.
Modern African tribes are an endless source of inspiration since their looks never cease to amaze.
Contemporary American Indians and the African tribes can also contribute their themed outfits and events to make any character look unique without making a deep dive into history as they managed to preserve their culture till present day. Moreover, almost every contemporary nation has their distinctive appearance to get transferred into a game.
The advice above comes from my personal experience at Game-Ace where we use many references to create a character for a game. For example, when developing Forge: Ymil’s Revenge, a PC adaptation of a popular board game, we drew our inspiration from The Elder Scrolls; for Archy, the Rabbit we reminisced the children books; during Hexagonium development, medieval fantasy lore was our raw model to ensue.