Part of an ongoing series of 5e (2014) and 5.5e (2024) Rules notes.  

Everyone hates Encumbrance rules

That’s a generalization, so suspect, but in my multiple decades of playing and DMing D&D and other FRPG / TTRPGs, I have yet to find anyone who wants to keep track of all the things they are carrying and their weight and have that impact how their character performs.  Conan and Legolas and [insert fantasy hero here] never worries about Encumbrance — why should I?

The only people who have any use for Encumbrance are GMs, as a check against player characters carrying around golf bags full of specialized magic swords (“Hmmm, a Flametongue for this encounter, I think”) and, more importantly, on player characters stripping the Temple of the Really Rich Lich of its 500,000 gold pieces and its diamond altar and the three giant jade statues with gems the size of toaster ovens for eyes.

In other words, Encumbrance is a tool for managing edge cases and, in some cases, exploits, and, frankly, can be skipped unless those come to pass.

Indeed, the D&D Rules themselves actually make that case. For 5.5e (2024), the PHB says on p. 20:

Carrying Objects: You can usually carry your gear and treasure without worrying about the weight of those objects. If you try to haul an unusually heavy object or a massive number of lighter objects, the DM might require you to abide by the rules for carrying capacity in the rules glossary.

The game should be fun. If a mechanic stops it from being fun, ignore the mechanic. But if lack of a mechanic stops it from being fun, be ready to use it when you need to.

So how about the rules?

The basic rules for Encumbrance are the same between 5e (2014) and 5.5e.  The only difference in significance is that 5e calls it Encumbrance and 5.5e calls it Carrying Capacity.

The underlying numbers, though, are the same, just differing i how they are presented.  5e gives some formulae and then a series of exceptions and extrapolations. 5.5e presents a table, which is a much clearer way of doing it, so that’s what I’ll use here.

Creature Size	Carry	Drag / Lift / Push *
Tiny	STR x 7.5 lbs.	STR x 15 lbs.
Small/Medium	STR x 15 lbs.	STR x 30 lbs.
Large	STR x 30 lbs.	STR x 60 lbs.
Huge	STR x 60 lbs.	STR x 120 lbs.
Gargantuan	STR x 120 lbs.	STR x 240 lbs.

^{*If you are dragging / lifting / pushing a weight greater than you can carry, your Speed drops down to 5 feet. If the weight is beyond the D/L/P level, you cannot move it.}

That’s pretty much it:  Size (basically your ability to balance a heavy load) and STRength (your ability to overcome inertia and gravity).

The numbers calculate the same between both 5e and 5.5e, so easy peasey.

(The variant rule in 5e, PHB 176, abut encumbering and heavy encumbering and their effects on your die rolls and speed, are not carried over in 5.5e, which is probably a good thing.)

The rules don’t explicitly state it, but presumably burdens can be shared. The math probably gets a bit dodgy, but I would let STRength be additive here, with some sort of proportion around the creature sizes of the folk sharing in the carrying.

Don’t ask me to factor in how having a wheeled setup (e.g., a cart, rollers, etc.) affects all of this if it’s the players pushing/pulling it.

A bit of science (maybe)

In real life, based on military studies:

• Humans can carry around up to 20-25% of their body mass without incurring  significant additional fatigue in combat.
• Outside of combat, it can go up to 30%.

I’m not suggesting using that to craft your own Encumbrance rules, though — because everyone hates Encumbrance rules.