I'm thinking about using it for a future 1e open-table and public campaign, so I had to adapt it a little. Here is my ruling for adapting it for OSRIC or 1e:
- It doesn't replace armor encumbrance, it only replaces weight encumbrance.
- The movement speed threshold of 7/4/0 for 40/30/20 is replaced by other thresholds based on Strenght, see in my next comment;
- Strenght doesn't allow to carry more, as the sheet represents the volume you can carry (you can't have 2-3 backpacks); it allows you to be less slowed by weight and also makes you able to carry incapacitated persons or heavy objects in addition in your arms, if you have exceptionnal Strenght (see also next comment).
New thresholds for 1e (I didn't do for under 8 Str, but you can iterate) :
8-11 Str = With 8 free slots you have speed 40', 5 = 30', 2 = 20', 0 = 10'.
12-15 = 7/4/1/0.
16 = 6/3/0/NA, meaning at 0 free slot you're at 20', you can only be more encumbered in special circumstances.
17 = 5/2/0/NA.
18 = 3/0/NA/NA, meaning under normal circumstances and without armor, you can't go under 30'.
18.01-18.50 = 9/10/NA/NA.
18.51-18.99 = You are always at 40' without armor, and can also carry a person/object of around 150lbs in both arms at speed 10'.
18.00 = Same, but you can carry either one person/object of up to 150lbs while staying at 40, or one of 300lbs (or two of +-150 lbs, one in each arm) at 10'.