A very important detail about HackMaster 4e was that their license with WotC for the AD&D 1e things allowed them to publish a parody of AD&D 1e. They absolutely

A very important detail about HackMaster 4e was that their license with WotC for the AD&D 1e things allowed them to publish a parody of AD&D 1e. They absolutely set out to create a fun and playable game (and IMO succeeded), but everything was contractually obligated to have an element of ridiculousness. On top of the generally lighthearted and joking prose, a big part of how they did this was to take the convoluted parts of 1e that later editions simplified away and instead make them over the top. 1e had lots and lots of overly specific lookup tables for things which later editions replaced with more general rules, so HM doubled down on that and made the tables even more gratuitously detailed. If you set aside the humor aspect, HM is a game that plays very similarly to 1e, but more fleshed out and with a lot of assorted improvements.