I've got a few house rules that stray from the White Star as written, but that's not surprising, as I've added a half dozen or so classes to the StarSlinger setting thus far.
- First, I've expanded the bonuses for high stats slightly. A score of 13-16 gives a + 1 and a score of 17 or 18 gives a + 2. Nothing huge, but it can me a life saver.
- Death is at zero HP, with the ability to save vs death to hold on until help arrives. The roll to save is adjusted by the negative amount of HP the PC is at, so going down to - 5 means a minus 5 on the save to no die. Natural 20s always save.
- If you want to attempt something not covered by the rules (and as this is an OSR game, it's quite likely to occur multiple times per session) such as picking a lock, hacking a computer and the like, it's a save adjusted by any relevant stat bonus and a modifier chosen by the GM (me) based on difficulty. Covers a whole lot of ground this way and does not slow down play.
Those are the main ones thus far. There are others that aren't fleshed out yet and I'm not even sure they'll come into play (or are even needed)