The Black Hack by David Black (TBH from here on out) is one of my favorite rules-lite games on earth (maybe even on Mars?). It is simple, streamlined and oh so deadly. Coming in at 20 pages, this small system comes with Rules, Equipment lists, Spells and Foes to fight, making this invaluable for the GM on the move.
The classes available are Warrior, Thief, Conjurer, and Cleric. Clerics get access to spells at level 2 (sorry fans of 1st level Clerics slinging spells). Ability scores are generated in the usual 3d6 rolled in order of ability, which is Strength, Dexterity, Constitution, Intelligence, Wisdom, and Charisma.
It is a d20 system but with a twist. Instead of rolling against an opponent’s armor class, you are trying to roll under your relevant ability score, i.e. under your strength score if you are attacking in melee and under your dexterity if you are attacking at range. “But what about armor!?” I hear you asking. Well, that’s another place where TBH is different. Instead of armor increasing (or decreasing) your armor class, armor gives a certain amount of damage resistance based on the type of armor worn and the character’s proficiency with that armor type. The armor will decrease all incoming damage, but only to a certain degree. Each armor type is assigned a number and once damage exceeds this number damage is dealt out as normal. This is to represent the character getting tired or his defenses being overwhelmed. This system is ok since armor points come back after a character rests, but I prefer a more traditional AC system with a roll-over mechanic to be honest.
Another unique thing in the game is the usage dice system. This is used as a way of tracking the amount of an item you have left, such as oil in a flask, holy water in a vial or torches left. The items that have a usage die associated with them will be designated on the item list with either d4,d6,d8 or d10. When you use said item you roll the corresponding dice. If you roll a 1-2 the dice goes down to the next level dice until you reach the d4. IIf you roll a 1-2 on the d4 then you run out of that item. I like this method because it keeps bookkeeping easy and stocked items unpredictable.
Overall, this is a great game. There are some aspects that people don’t like, such as the usage dice or the armor system, but the great thing is they can all be house ruled away. I for one enjoy the system as it was designed. This is the perfect system for an experienced GM to run some OSR noobs through the gaping maw of an endless dungeon. While not perfect (one-hand weapons are absent from the item list, though easy to put in) and the rules do assume some familiarity with RPGs and the OSR, this is an excellent system. Take into consideration that the whole system weighs in at 20 pages and you have a real winner.