Most fantasy roleplaying games are set in worlds where the presence of gods is strongly felt. Source materials for these realms often detail times throughout history where the gods have directly interfered with the affairs of mere mortals. It is usually assumed that most characters in these games not only believe in the gods of these worlds, but also worship them to some degree. The most extreme case would be priests and paladins who are only able to tap into magic because of their devotion to a particular god. Fighters and other classes may also worship gods because of superstitious beliefs or just blind faith, but the gods have less of an impact on their activities. It could be said that every character in a fantasy RPG is religious to some extent, but is it possible to play an atheist character in these games?
Denial of the existence of gods is a difficult position to hold in a world where these beings occasionally walk amongst the characters. How can a character be an atheist when they have literally looked upon Bahamut? How much more evidence does one need? The simple answer is the character believes that these beings exist, but that they aren’t actually gods. They are just able to tap into powers that seem to be beyond the reach of normal individuals. Think about it this way; the gap in power between a human wizard and Tiamat is much greater than the gap between a red dragon and Tiamat. Along the same line of thinking the gap in power between a field mouse and a red dragon is much greater than the gap between a human wizard and that same dragon, but field mice don’t generally worship red dragons as gods. An atheist character would simply believe that the power these so-called gods wield is attainable by everyone. It is just a matter of learning how to close the power gap.
So which class would be the most likely to deny that the gods are gods? Clearly the true believers like clerics and paladins are out. Fighters get no benefit from being religious, but they say there are no atheists in fox holes. Thieves are probably too superstitious to not believe in some higher power. The most likely candidate is the wizard. Wizards don’t receive their magic through divine blessing. The have to learn it and they always want to learn more. They constantly study spell books and lore in an attempt to understand the nature of magic. They perform experiments to create new spells and magical items. Wizards found universities to teach magic and conduct magical research. All of this is in an effort to unlock more and more powerful magical energies. Extremely powerful wizards are often described as trying to unlock the power of the gods. A cleric or a paladin would never dare to believe they could wield as much power as a god since that would be considered blasphemy. Wizards strive for this power because they simply don’t recognize the divinity of these beings.
So now that the argument has been made that wizards can be played as atheists the question is why a player would choose to do so. The easy answer is that it would provide conflict, the kind that makes for an interesting story. Wizards are often played as arrogant and abrasive so playing them as an atheist really just stretches this out a bit. An atheist wizard would have friction with any clerics or paladins and probably even druids. Imagine playing a wizard who mumbles about “superstitious mumbo-jumbo” under his breath every time the cleric prays to gain their spells. This wizard would also be the one to look for rational explanations in situations and see past the machinations and schemes of cults and demagogues. Basically an atheist wizard can be the scientist in the group to complement the muscle, the priest and the rogue.