First, an interlude. Skip to paragraph 2 for the punchline. My favourite edition of D&D is Moldvay Basic, the one between the Holmes and Mentzer editions. It was much clearer and more complete that Holmes, but much more concise and generously writen than the more wordy and better known Mentzer edition. Your characters were properly heroic. Can your character ride a horse? Just note how you learned to do so on the character sheet. Want to be able to swim, or navigate or helm a ship? No problem. Then there was the 'you can try anything' rule in the GMs advice section. If there isn't a rule for something you want your character to try, just roll 1D20 against an appropriate stat and try to roll lower, maybe with a modifier. Just like that, D&D got a general purpose task resolution system that made it a truly flexible, heroic system. But it was not to be, Mentzer and AD&D crushed the game under the "If it's not on your character sheet, you can't do it" ethos of doling out permission to be able to try to do things via feats and profficiencies.
The Black Hack jumps the tracks of the whole OD&D, OSR movement into an alternate timeline where this simple attribute check based mechanic from one edition of Basic D&D becomes the hart of the game. It's not just dialing the clock back to that key moment, it takes us back to the future again with a carefully judged selection of fun new little tools and mechanics to create a tight, minimalist but very capable system. It has the equivalent of feats and such, but rather than grant permission to try at all, they make it easier to succeed. Now that's how you do it! First edition was very spare, but the second edition clarifies and organises the system and adds a host of support meterial that make it into a complete game and great value for money.
I've no idea if David Black even knows about Moldvay D&D and that cute little rule, no reason why he should. What he's built here stands on it's own as easily my favourite of the OD&D/OSR games.
[5 of 5 Stars!]