AD&D 1E Rules that are kinda cool but everyone forgot

[Koloth]

Death at -10 had to have come in a lot earlier than 1989 (2e release), as we were using it by about 1983 (or maybe sooner?) and it's not something our crew would have invented themselves.

Could have been introduced in a Dragon. A fair amount of the stuff in those was deemed 'official' rule content even if optional.

 

[Lanefan]

Could have been introduced in a Dragon. A fair amount of the stuff in those was deemed 'official' rule content even if optional.

Probably was, but I don't know when.

 

[Nikosandros]

Death at -10 had to have come in a lot earlier than 1989 (2e release), as we were using it by about 1983 (or maybe sooner?) and it's not something our crew would have invented themselves.

It's in the 1e DMG. If you are reduced exactly to 0 HP, you do not die, but are unconscious and lose 1 HP per round until you reach -10. Optionally, the range which makes a character unconscious, can be extend to -3.

 

[Marc17]

Hirelings were usually overlooked in my experience. I always liked the rules for hiring a gem cutter in the DMG which could improve the value of your gems or ruin them. Pg.30
A weird one that came up when I was looking for rules dealing with blocking movement and such, is that a medium character can be attacked by a maximum of six opponents, and each only through one of the eight cardinal direction (six if using hexes). DMG pg.69
I am sad I've never seen all the rules for collecting eggs or the young of various flying creatures to raise as mounts used in a campaign. Griffon MM pg 50
For that matter, I've never heard of a dragon subdued and then sold. MM pg 30