Provided here are some rules for updating the Midnight campaign setting to D&D Fourth Edition. They are home rules for my personal game, though other DMs are free to borrow them. All intellectual property rights are forfeited in favor of Fantasy Flight Games' previous copyright for the setting.
The classes of D&D feel and act slightly differently in the world of Aryth. Below are some notes on salient changes that players should consider.
All divine classes in the core setting of D&D pledge themselves to a specific god or pantheon. In Midnight, the gods are absent, cut off from the world, except for the Dark God Izrador. As a result, player characters following divine classes do not pledge themselves to any deities and so do not qualify for any feats, powers, paragon paths, or epic destinies which require one to be a follower of a deity. They still qualify for domain powers (introduced in Divine Power) but a character may claim access to no more than two different domains. In essence, a divine character is drawing on his own convictions and spirituality to power his spells without access to other gods. This is not true of servants of Izrador, of course, which is why the Dark God's clergy are so prolific compared to divine champions of good.
The following are new house rules to incorporate important mechanics from the Midnight campaign setting.
When Izrador was cast down by his brother gods, a breach between the mortal realms and the domain of the gods forever changed the world of Aryth. The most obvious change was that mortals no longer had access to the other gods of the heavens and so all churches immediately failed and their works were lost. Mortals have since learned to draw upon their own spirituality for power, but this divide also created a the terror of the Fell that continue to haunt Aryth to this day. Deprived of paths to the afterlife, far too many souls are trapped in their mortal bodies and forced to rise as undead abominations.
When killed, a creature with the Natural origin and an Intelligence of at least 5 must make an immediate saving throw. This saving throw is in addition to the three saving throws that dying characters make. At 11th level, characters receive a +2 bonus to this save; at 21st level, this bonus increases to +4. Failure means that the creature rises as an zombie within the next 1d4 days. A natural roll of 1 indicates a critical failure and means the creature rises immediately as a zombie. Success means that the creature moves into the spirit realm, a chaotic and tangled place just beyond the planar bounds of Aryth.
Creatures can choose to give in to their fate and rise as fee-willed Fell creatures. Doing so means that the creature will rise as a revenant in 1d4 days, but he will earn 1 point of Taint for allowing his soul to be used this way. Alternatively, the creature may choose to rise immediately as a revenant and take 2 points of Taint.
If a corpse is beheaded or burnt to ashes, there is no chance of the creature rising as one of the Fell, even voluntarily as a revenant. Beheading a corpse is the same action as a coup de grace.
In the lands under Izrador's control, most citizens are illiterate. Teaching another to read is enough to get the teacher and student both sold into slavery. As a result most taverns and other public places must advertise using only pictures since the owners and customers are all illiterate. There is no specific mechanic for illiteracy other than to assume that all Erenlanders (aside from those with the Ritual Caster or Alchemist feats) are illiterate. Characters from outside of Erenland can choose whether or not to be literate, a choice which shouldn't adversely affect them in Erenland, and Erenlanders can choose at character creation whether they are secretly literate. Studious character classes such as clerics and wizards are not necessarily literate (they may have learned all their spells and history by word-of-mouth or trial-and-error) but anyone with the Ritual Caster or Alchemist feats need to use books and so cannot be illiterate.
Because of the slight disadvantage to being illiterate, the DM may choose to provide a +1 bonus to Insight checks to read NPCs for illiterate characters. Such individuals have to rely on their own perceptions to understand situations since they cannot rely on store signs or other such abilities and therefore they pay more attention to body language and non-verbal cues. This bonus should be applied as the DM sees fit; it is not guaranteed.
Information on the races of Midnight in Fourth Edition can be found here.
The dark deeds that many must commit to simply survive under Izrador's rule has it's consequences. Doing evil or at least morally questionable acts can earn characters Taint points. A creature has an ongoing Taint score which is modified according to certain circumstances, described below. When an evil creature attacks with a power that targets Will, it receives a bonus to the attack equal to the target's Taint score. Getting rid of Taint points is difficult but can be done through truly courageous acts.
Few now can claim to be experts on the past except for the long-lived elves and the proud dwarves, but Eredane has not always been gripped by Izrador's jealous hand. There were three ages previous to this, each of them marked by a cycle of growth, senescence, and then an awakening of the Dark God. The First Age was a time of new colonies and the founding of cities, when the elves, halflings, and gnomes of Eredane built powerful nations and the Dornish men of the north carved out their own kingdom. When Izrador arose in the north, an alliance of elves, dwarves, and men, led by Aradil the Witch-Queen, defeated him and cast him back to his icy retreat.
In the Second Age, the Sarcosans invaded Eredane from their powerful empire across the sea and wrested the south from the elves and halflings before conquering the Dornish kings of the north. Izrador tried again to conquer all and struck when the Sarcosans had lapsed into smug inertia. Queen Aradil led her elven troops to battle again and joined dwarven armies and Sarcosan and Dornish troops in the fight against the Dark God. Even with so might a host, the Lord of Shadows might have won if not for the dragons. The might dragons entered the fray and cast Izrador back once more before vanishing themselves to their secret homes.
In the Third Age, Izrador took a more subtle, crafty approach. Queen Aradil began to find patches of Izrador-worshipping cults in her forests and the dwarves discovered traitors among their numbers as well. A great Dornish lord disappeared while hunting, only to return seven years later as the leader of Izrador's orcs. The Last Battle is fought, swallowing up the human lands with surprising speed. Though the Dorns and then the Sarcosans lead massive armies against the Dark Lord, defeat seems assured in hindsight. Izrador's minions were already in place when his armies first appeared on the northern steppes and his siren call of dark rewards toppled as many rivals as his armies did.
For the last century, the people have Eredane have lived through an ever-darkening Last Age. Books are burned, monuments toppled, and people are scattered so that their national pride and historic legacies cannot serve as rallying points against Izrador's rule. The elves and the dwarves continue to wage their war against the Shadow but they have lost gradual ground over the decades and gained none. Today, year 99 of the Last Age, Izrador is no longer a foe. He is a master.
Life under the Shadow is harsh and unforgiving. Most adventurers risk execution simply by the things they carry and the friends they keep…
The continent of Eredane once had a normal, balanced climate with seasonal changes in both the north and the south. Since the coming of Izrador, however, and the wanton use of magic by his legates, weather has taken a sinister turn across the lands. The north is shrouded in snow nearly year-round and the south is wracked by sudden, sweeping storms. The Kaladrun mountains, home to the dwarf clans, are constantly frozen and dire winds race off their glacier-covered peaks. The effect of these weather patterns is to create more fear among the populace about travel and to keep them at home. Those who dare to live free-roaming lives still must constantly contend with these threats on the road.