Various RPG systems include a paladin character class. Invariably they are agents of 'good' , truth , justice and the 'path of the pure'. They are usually holy magic using warriors that strive to rid the world of 'evil' by the simple expedient of thrashing the living daylights out of it. Commonly, the physical manifestations of 'evil' come along in the form of monsters - Dragons seem to head up the list of favorites and demons just behind them. Another favorite pastime of paladins seems to be rescuing maidens from said dragons and demons
It seems to me that the majority of players play paladins along the lines of a romanticized knight in shining armour that will tilt his lance at anything remotely like a dragon without a second thought. This is insulting to players and knights alike, for it does not attribute either with any intelligence or common sense. The other common theme is that all paladins must be 'good' and therefore serve a 'good' deity. The problem I have with this is this ... Although the RPG systems tend to use a pantheon deity setup ie multiple gods loosely based on the ancient gods of earth plus more deities included for non-human races - the paladin seems to be stuck with catholic premises and principles. They are meant to be chaste and charitable, the first to defend the weak, old or helpless ( as long as they are 'good' weak, old or helpless ). The paladin is said to be a fanatic.
Nowhere, does it say that a paladin has to be a christian ( I am not defaming christianity - I am trying to say that RPG paladins need not be tethered to the restrictions of our christian knights of history, though they may have other restrictions put upon them by the religion that they do subscribe to ) there are plenty of religions to chose from and many philosophies on life - which brings me to my next point ...
In a fantastical world with elves, dwarfs, orcs, goblins, humans and many other races co-existing or not, what is normal? How can we fit judaic-christian positions of good and evil into a society of such a disparate makeup. In some of the societies that we set our stories it is reasonable to assume that the code by which they live by will be different to the laws that we know. It is very likely that the conditions of living are very different to what we are used to ( otherwise - why bother playing a fantasy roleplaying game ) and survival will require markedly different attitudes.
Unlike our semitic system - RPG deities tend to have portfolios - more like Norse, Greek or Roman gods. So you will have a god of justice , a god of soldiers who is different to the deity of warfare and so on - this, in my mind, blurs the definitions of what a paladin should be fanatical about. If you serve the god of justice are you worried about under whose laws people live - as long as justice prevails? This does bring us into an interesting and sticky area of ethics and it also provides us with a brilliant opportunity to explore them via roleplaying.
Play your paladins with intelligence and pay attention to the religion that they serve and the society that they live in. Make sure that any racial or cultural intolerance that you manifest belongs to your character and is not born of your own conditioning. Most of all - have fun!