The world is locked into a never-ending cycle. Rising from barbarism, small, isolated villages begin to band together under a common ruler for mutual protection. Slowly, these villages spread out into the surrounding wilderness and become nations. Their armies become larger and stronger, eventually conquering nearby nations and forming an empire. But sooner or later, that empire will fall — its provinces will splinter, its people will scatter, its borders will crumble into the wilderness, and eventually only a few points of light will remain to keep the fires of civilisation burning until the cycle can start anew.
What causes these empires to fall, time and again? Why don’t they reach ever-greater heights of progress until they span the world and proclaim an end to history? Sometimes, they are weakened by decades of internecine warfare, leaving each too drained to carry on. Sometimes, they are torn apart by vicious succession struggles, brother turning against brother until none are left to carry on the fight. All-too-often, the ruling classes grow fat and corrupt, draining the imperial treasuries for their own decadent pleasures until the empire is sucked dry and withers away.
Most often, however, creatures of darkness — monsters — are the cause. Some monsters are so powerful they can slaughter an entire village by their lonesome. Others breed so rapidly they will overwhelm all opposition by sheer numbers if not kept in check. Others still are more insidious, hiding amongst ordinary people, preying on and corrupting them and never revealing their presence until far too late.
All these and more combine into a devastating onslaught on nations and societies, destroying them from within and without. Civilisation always hangs by a thread. Ignoring the menace of darkness only causes it to grow. For society to survive, prosper, and grow, the monsters preying upon it must constantly be fought. The armies of nations and nobles alone cannot do this — while they may be able to stand firm against invading hordes, they are too slow, too defensive, too limited in experience with the vast variety of darkness, far weaker than many of its scions, and above all too focused on patrolling and protecting only the territory of those they call their lord.
Darkness acknowledges no borders, and thus civilisation needs its own defenders who can go where they are needed to face it. In order to give civilisation a fighting chance, a new class of oathbound warriors has risen, who will not only defend society from the monsters that attack it, but strike fast and hard into the enemy’s territory and stalk the monsters into their very lairs.
They are the Keepers of Light, and holding back the darkness is their ultimate reason for existence.
Most of them do not survive their first year.
The Keepers of Light and Darkness is a heroic-scale dark epic fantasy setting for GURPS. It draws inspiration from many different sources, most heavily from JürgenWerks’ Doomed Slayers (or more particularly, from the same discussion thread that became the Doomed Slayers supplement). Other primary sources were BioWare’s Dragon Age series, the works of Brandon Sanderson, and both the Dungeon Fantasy and Monster Hunters genre toolkits for GURPS. Minor sources are too numerous to thank individually.
You can find the current index of the setting, always in flux, here.