Identification

As my research brings me into characters that fall into specific factions I have found that an important, almost defining aspect of this is the ability to identify the way in which a character visually presents itself in order to identify it.
Identification in videogames falls among the most important aspects of defining not only visuals but gameplay also, specifically in multiplayer-focused games, such as the player needing to identify the opposition quickly and easily.

In this case, I am focusing on visuals, and how might the story and setting define how characters are set apart from one another, as characters must visually reflect what it is they represent as a culture or world of people.

As an example, it is entirely possible to visually identify our human race (In comparison to any other race of species out there in the universe ;) ) by how we typically wear clothes as a two piece, how our architecture is generally taller than our heads, how our form of travel is carried out on flat paths that stretch for miles.

The question I've then spawned from this is 'Well how else would you do it?' Though my focus isn't designing something alien, what I do want to do is think outside the box with design and in what ways we identify characters.

Good examples of opposing or differentiating factions of characters will contain good uses of shape, pattern and colour coding, this accounts for both day-to-day examples and ones in games and movies.

These are examples of identification for cultures, clans and authority that we have today.
I felt it was important to list literal identification also, like the passport or drivers licence as this is a direct window to a person/character, less visually but it will certainly inform their age group and country of origin, which the mind will stereo-typically draw up a mental image for alone.
Every one of these examples has a form of symbolism behind shapes and colors that are used in their design and that we now will commonly associate with that particular thing.

There is a heavy amount of narrative that lies behind shapes and colors used to identify factions in games and TV. Some are for aesthetics, and others tie directly into function. As games have become heavily multiplayer-based nowadays, we now typically associate the colors Red and Blue with multiplayer;

 If you are red, the blue's are the enemy, and if you are blue, the red's are the enemy.

In Star Trek, the ranking and department of a starship officer can be identified through their uniform. Yellow for Engineering/Tactical, Blue for Science and Red for Command. 

The rule of shape is also a heavily defining visual when identifying between oppositions. Circular shapes being friendly and more approachable are commonly associated with good, while pointed, triangular shapes are associated with the opposition and evil.

The games Gears of War and Tribes Ascend both heavily use this rule in character design, though sometimes not obvious, it is enough for the player to distinguish between the two opposing factions.