Slot-based or item-counting encumbrance is popular these days, and for good reason. It's easy, requires no calculations, and it works. Basically, instead of tallying up the weight of a bunch of individual objects, players just keep a list of how many items they are carrying. Cross your maximum threshold and you are encumbered. Items carried are assumed to average out in weight and bulk. The number you can carry may be fixed for all characters, or may be modified by a Strength stat or the like, or by the carrying conveyances your character has. Don't count your amulet or your spoon. Tiny stuff doesn't get counted. Big stuff counts as two items or more.
Carrying ability becomes a transparent limited resource. Resource management is popular among players who hearken after the feeling of early RPGs (even though most players in the old days scarcely bothered with encumbrance, in my experience), but tallying numbers is not popular. This method suits both preferences. Arguably, this simple system is more likely to get used than a complex one, too, so keeping it simple makes encumbrance matter more.
When I started adapting and modifying the old rules I like into my home rule set, slot-based encumbrance was exactly what I wanted, but I didn't know how pervasive slot-based encumbrance had become out there in the land of indie retro game designers and clone warriors. (More on a few of those below.) I was unaware of much of that. My inspiration was coming from the solo gamebooks of my youth in the early '80s instead.
I don't know for sure where slot-based encumbrance rules originated, I can't find any earlier source than the board game Talisman in 1983. (It's still a fun game in the current edition.) Players in Talisman, published originally by Games Workshop, have individual characters represented by character cards. Objects (equipment, magic stuff, etc.) in that game
are represented on smaller cards that you find (draw from the adventure deck) as you explore the board.
Your character can carry (i.e. you, the player, can hold) only a fixed
number of Object cards at once, typically four. If you find new stuff, you may have to
drop old stuff (which, then, other players can pick up if their character lands on
the space where you left it). You can also find Objects that let you carry more
Objects, find a Porter or a Horse & Cart that can carry more, etc.
But the number of Objects you can carry is fixed and it's a part of the
game's strategy to keep the best stuff and leave behind the stuff that's less useful.
Then there were the Lone Wolf game books, also from the UK. Published from 1984 onward, they were choose-your-own-adventure books in which your selection of abilities from a long list for your character (who is basically a psionic ranger-monk, like a fantasy Jedi knight) made all the difference, and you gained new powers and equipment continuing from book to book. You also used ten-sided dice to resolve combat. The English author, Joe Dever, used the setting he had been developing with his D&D game since 1977.
The Lone Wolf books fixed a limit on the number of items you can carry. This is slot-based encumbrance, in today's terms. Here is the relevant excerpt of the rules from the first book:
- The maximum number of weapons that you may carry is two.
- Backpack Items
- These must be stored in your Backpack. Because space is limited, you may only keep a maximum of eight articles, including Meals, in your Backpack at any one time.
- Special Items
- Special Items are not carried in the Backpack. When you discover a Special Item, you will be told how to carry it.
- Gold Crowns
- These are always carried in the Belt Pouch. It will hold a maximum of fifty crowns.
- Food is carried in your Backpack. Each Meal counts as one item.
Any item that may be of use and can be picked up on your adventure and entered on your Action Chart [LVW: this is the character sheet] is given capital letters in the text. Unless you are told it is a Special Item, carry it in your Backpack.
This is the direct inspiration for my home rules.
The lines between board game and game books and role-playing games were blurry in the early '80s. They shared a fan base, and I was in it. This is part of my current nostalgia.
Anyway, very soon this kind of carrying capacity rule showed up in RPGs.
As far as I know, the first fully-fledged role-playing game to use slot-based encumbrance was Toon (1984), by the experimentally-minded game designer Greg Costikyan. Toon was one of the TTRPGs that came out in a wave of comedy-oriented games like Paranoia (1984) and the Ghostbusters RPG (1986).
In Toon, you play a cartoon character in the style of "classic cartoons" that used to show on broadcast television, like what I watched as a kid every Saturday morning. As cartoon characters can just whip objects out of nowhere, your character can, too, but you are limited to a predetermined list of eight items, four being "normal" items, that you carry around invisibly by cartoon physics.
Soon enough, though, a "serious" fantasy RPG adopted the item-counting system. Dragon Warriors (1985), a British fantasy role-playing that I never saw in the USA, seems to have been inspired by Talisman or Lone Wolf in its encumbrance rules. The initial rule book says:
Rather than devise a complex chart of weights and 'hindrance factors', the simple rule in DRAGON WARRIORS is that an average character can carry ten items roughly equivalent to a weapon in size and weight.
Such items include:
a quiver of arrows
a case of quarrels
a lantern or torch
a sack of coins (about 150)
Small items such as rings and amulets are not counted. Armour is also excluded from this - the encumbering effect of heavy armour on a character not trained to use it is already allowed for in the combat rules.
Weaker and slighter characters cannot carry as many items as this. A character of Strength 3, 4 or 5 is allowed only six items. A character of Strength 6-8 is allowed eight. Powerful characters can carry more. A character whose Strength score is 13 -15 can carry up to twelve items. A character with a Strength of 16 or more can carry fourteen items.
There are some occasions when you will have to make an on-the-spot ruling. For example, the player characters find a locked chest containing between one and two thousand silver pieces. They can't break it open and decide to take it along with them. This many coins would normally count as 'ten items' for encumbrance purposes - but there is also the weight of the chest to take into account. A character of above average Strength could carry it on his back, as long as someone else took care of his weapons and regular equipment in the meantime.
(Note of the explicit advocacy of "an on-the-spot ruling" on the part of the GamesMaster.)
With the coming of GURPS in 1986 (and its combat-only precursor Man-to-Man in 1985), we see a renewed emphasis on tallying weight of individual objects carried again. The explicitly stated reason for this in GURPS was that it is supposed to be generic and universal (the GU of GURPS). Any game system that used real-world units of measurement could be converted back and forth with GURPS by means of those units of measurement. GURPS supplements were thus supposed to be useful for any other game. Needless to say, slot-based encumbrance did not fit this way of doing things.
When it comes to more recent games, I have seen players giving credit to Lamentations of the Flame Princess (2009), one of the more popular OGL home-rules rewrites of D&D, for its innovative encumbrance system. I finally looked up its encumbrance system and yes, it looks like it would work. Players tally encumbrance points based on number of items carried. It's not quite as straightforward as tallying items carried directly, but it's probably far more effective at regulating encumbrance than adding up every quarter-pound, half-pound, etc., object one is carrying, or the weight of items in "coins."
Then there are more recent and popular rules-light games like the excellent indie dungeon adventure game Knave (2018), in which item slots become, to an extent, the basis for character abilities. As its author, Ben Milton, writes in the game, "Slots are also the key to character customization, as a PC’s gear helps determine who they are." The gear needed to cast a spell (usually a scroll or book) takes up one item slot per spell (rather than "spell slots" in the more recent D&D jargon). This seems like a great way to introduce young new players (Knave's original audience) to resource management and character development simultaneously in RPGs.
Anyway, I'm glad to see that my home rules item-slot system is inadvertently aligned with the times. I thought players today would balk at the item-counting system either because it's "unrealistic" or because it is unlike the early D&D rules, on which there is much fixation, but it turns out that slot-based encumbrance has some popularity.
If anybody knows of a simple item-counting encumbrance system in role-playing games from before 1983, please let us know. Otherwise, I think I may have dug up the roots. We can thank Talisman, Lone Wolf, Toon, and Dragon Warriors for planting the seeds for what is now a popular component of fantasy game rules.
EDIT 3/10. JC has pointed out the antecedent of all of these in the second edition of RuneQuest. See the discussion below!