If you're curious about the Black Hack game system I'd like to direct you to a very comprehensive review by Sophia Brandt over at die Heart (which you can find here). A quick recap: The Black Hack is a very rules light game with some nods to old school, but it has some newer material. For instance, instead of a +1 or -1 to your roll, the Advantage / Disadvantage mechanic is used (ala 5e and from what I'm told Barbarians of Lemuria). The game has four classes: Fighter, Thief, Cleric, and Conjurer (ala the Mage). The core book does not mention the races however, so that's where the Race Hack can come in.
The Race Hack
System: Black Hack
Pages: 19 (includes cover)
Place to purchase: Drive-thru RPG's link
So what is it?
The Race hack is 19 pages divided into two chapters by its developer Marc Craddock (of Crossplanes Studios). The two chapters are divided partly in races that reflect later 1e and future editions of D&D, specifically they hate little stats that alter characters stats. Actually, that's option #1. In this chapter Craddock gives us two options. One is stats, the second option gives a character special powers that resonate with the theme. Giving an example for a Gnome:
+1 CON or INT
Has Infravision to a distance of Far-Away
(1/day) A Gnome can automatically succeed on a WIS test to disbelieve an illusion.
(1/day) When a Gnome succeeds on their attack roll against a Goblin or Kobold they may deal critical damage.
For the most part I like the options presented, though I feel some of them are a little too narrow. Like above- Goblin and Kobold might be a little too specific for my tastes. I'd probably broaden it to Goblinoid / Reptilian creatures ala Pathfinder. What this pdf does is provide an excellent base inspiration for a GM to write their own stats.
Races that are given stats include: Drakes (think Draconians or Dragonborn), Dwarf, Elf, Gnome, Half-Elf, Halfling, Half-Orc, Human, Tiefling.
Interestingly Aasimar, the angelic counterpart to the demonish Tiefling are left off. Where is our half-angels out there? Does everybody really like being mister badass by playing Tieflings?
The second chapter is shorter and presents the option of "Race-as-Class". You get three new racial classes including the Dwarf, Elf, Halfling. Compared to the classes from Black Hack core you get Dwarves (Advantage on Saves vs. Magic, Poison, Death, and Disease. They have a Warrior's hit die and resting die), Elves (can cast spells while wearing any kind of armor or use any kind of weapon), and Halfling (Gain a bonus to range weapon attacks, extra armor points due to their height, and some stealth).
There are some trade-offs. Dwarves cannot use two-handed weapons or longbows. Elves have a lower hit-die compared to fighters (d8) and a terrible unarmed strike (d4) but they can wear any armor and wield any weapon while casting spells. Halflings have similar attacks and health as Thieves, but lose out on bonus damage, instead they get a Advantage on range attacks.
Summary: Like Black Hack you get your information presented concisely with no art cluttering the page. Each page represents a race, and as shown above with the Gnome, the racial modifications are nothing too crazy. As a fan of non-human PC's I really liked this supplement to Black Hack. It works both as direct stats and as a foundation/inspiration for me to build new races on.