Before we introduce classes unique to By Night, we have to look at the basic building blocks of a character.
Characters can belong to one of three "tiers".
Tier 1 characters are plain normal humans. They may well be exceptional in their background. A vampire hunter, a battle hardened veteran soldier and a scientist specializing in theoretical physics are all interesting roles to play, but they're fundamentally human.
Tier 2 characters are those touched or influenced by "the other". Whether they've studied ancient magical rituals, received alien implants or are the result of a super soldier program, they sit on the line between human and other.
The third tier is the "other". Werewolves, alien infiltrators and those infused with the power of a dark god.
The GM will of course have to determine what tiers are permitted, as well as what character types. Talk it out with the players.
What if the paranormal investigators have a werewolf friend? What if one of the group is an alien hybrid?
Don't be afraid to go with something you didn't anticipate, but don't be afraid to draw lines either, if it will make for a better campaign.
While ability scores can be rolled as the GM finds most appropriate, the default method is determined by your tier.
Tier 1 characters are rolled with 3D6 for each ability score, rolling each score in order.
For a character at Tier 2, roll as above, but generate three sets of ability scores, and select which set you will use.
Tier 3 characters roll their ability scores on 4D6, dropping the lowest die for each score. Scores are still rolled in order, but two scores may be swapped.
Alignments are handled very simply By Night. Most humans will be Neutral. Often this simply stems from a lack of understanding of the world. While individual humans may be "good" or "evil" based on a particular set of moral values, this does not change their basic alignment.
Lawful alignment in By Night is considered to be an active determination to preserve the world as we know it, and push back "the others".
In contact, a Chaotic alignment indicates a desire to destroy or radically alter our world, usually putting it under influence of "the others".
To serve as an example, let's look at a few characters:
A vampire hunter who have sworn to wipe out the undead, wherever they lurk and hide would likely be Lawful.
Another vampire hunter who is simply trying to protect their home town from the undead threat may will be Neutral. While they oppose "the others", they do so on a conditional or situational basis.
A cultist wanting to awaken the elder gods to destroy the world is of course Chaotic, but the scientist wanting to merge humanity with the alien overlords would be too, as he seeks to reform things in a non-human way.
Note that these very specifically are not "good" or "evil" in the conventional sense. A vampire hunter may have no remorse using innocents as bait, while a cultist may seek to enlighten humanity by merging us with the alien lifeforms.
The base class:
While each character class will have unique skills and traits, there are some fundamentals that apply to everyone:
Hit points, unless indicated otherwise are determined as 1D6 per level of experience. After 9th level, a fixed 2 hit points is earned per level.
Experience levels, attack rolls and saving throws are all resolved using the Fighter tables, for whichever OSR or classic fantasy game you are using as a base for By Night.