I am a “rules lite” GM. I hate it when narration or gameplay are bogged down by calculations or by having to look up tables in the rule book. But I am all in favour of verisimilitude, and I also hate it when player characters carry too much loot or gear. So it's quite a dilemma as to how to manage PC encumbrance.
In all honesty, in my 30+ years of GM'ing, I haven't found any satisfactory solution and, as a result, I've always ignored character encumbrance and relied on my judgement to referee situations like chases, maximum loot carried, influence of armour on skills, etc.
Now I have just stumbled upon a solution that seems simple enough that I want to try it out the next time I'm GM'ing Timinits and Trolls. Basically, here's how it works: there's a new (derived) characteristic called CAPacity. It is computed by taking the smallest score amongst STR, CON, and DEX, and adding 10 to it. This is the amount of stones the player character may carry.
So if Delh the Delver has STR 15, CON 19, and DEX 17, his CAP is equal to 25.
The other nice subtlety of the system is the following rule: “items which can be carried in one hand weigh 1 st. If you need two hands it weighs 2 st.” — this effectively removes the need to clutter up the character sheet with detailed weight calculations. For smaller items, 20 w.u. equal 1 st. [note– this is for encumbrance purposes only, since the maths don't add up: a T&T w.u. is equal to one-tenth of a pound, meaning 20 w.u. equal 2 lb, whereas 1 st is 14 lb].
A character who is too encumbered loses reactivity. The real SPD to be taken into account whenever it's needed is the lowest between “free” CAP and SPD. “Free” CAP is defined as the original CAPacity of the player character minus the gear and loot he's carrying as expressed in stones.
Delh the Delver has CAP 25 and SPD 17. He is carrying 5 st of gear; his “free” CAP is hence 20. Should the GM call for a SR on SPD, Delh would use his SPD of 17.
Now Delh is carrying 10 st of gear; his “free” CAP is hence 15. Should the GM call for a SR on SPD, Delh would use his “free” CAP of 15 instead of his SPD of 17.
Alternatively, the GM may use the difference between the lower “free” CAP and the SPD score as a malus for encumbrance-impacted Talents.
Delh the Delver has an Athletics Talent of 23. However, he is in the situation where he is carrying 10 st of gear and his “free” CAP is thus lower than his SPD by 2. Should the GM call for a SR on Athletics, Delh would use a reduced Talent of 23-2=21.