Building a machine from unused parts

I was reading something about the "forgotten rules of rpgs today", the ones that are usually handwaved or something. It listed three: item weight, crafting rules and XP. I'm not going to tell if this is true or not, but it made me wonder "could a ruleset be made using ONLY those, as the mechanical parts?" 

Here is an attempt for the skeleton. There is no setting or context, only rules; but maybe the latter might suggest the former.

You can carry (4+level) weight, or +2 weight and be encumbered; with items having set weights in a list. Characters fill one weight slot from their inventory when they suffer a wound. Leveling makes your character either stronger (and thus being able to carry and withstand more) or experienced with packing stuff so they are easier to transport. For now it remains abstract.

Certain actions cannot be taken while encumbered, as climbing a rope. Certain monsters are fast enough to catch you encumbered, but not when you're not. 

Certain items can be crafted from mixing 2-3 other items during downtime (as always, the full list of items and permutations is the heavy part of the game, but yeah it can be done). Certain mixtures are trickier than others and might require a roll with a probability fixed on the formula (X in 6 is sufficient). Mixtures can also have level requirements as part of their recipe.

You also have a chance to get mixtures "done" during an adventure, by rolling 1/2 your level on a d6. If you achieve it, it represents that your character had the intuition to prepare the item during the last downtime (so, every level represents your character getting more and more wise and foreseer)

Your party gets 1 XP whenever you recover 1 treasure, but you can only split it between party members if you have enough XP for everyone to receive equal share. (If you have 5 XP in the pool, and you're three party members, during downtime you can give 1 XP to every member and leave 2 XP in the pool)

level 1: 0 XP - level 2: 1 XP- level 3: 2 XP - level 4: 4 XP - level 5: 8 XP, etc

Combat having no rules at all means that fights have predetermined outcomes: they are either automatically won if the players fight (though it might have unwanted effects, like atracting more enemies, etc) or automatically lost if engaged, unless certain items are used (like flaming oil vs a troll, silver vs a vampire or using a smoke bomb for the party to flee). Now I think about it, it sort of feels like a LucasArts graphic adventure resolution: find the right combination and maybe it works; but with added level advancement. 

Even as I feel that this could work (It even makes the game diceless if we push it) I also think that it requires much work from the GM to decide ad-hoc (or for me, the author to decide preventivelly) if a single item is either worthless in a determined situation or, for the contrary, if its as powerful to obliterate the encounter. In the end, it can be interesting if you have a "dungeon" in which you can control many of the possibilities the players might try (like, for example, in a LucasArts game), but harder to implement in a larger environment with lots of different types of encounters and items.

So there is another approach, starting from the simplest combat system I could devise: When two people get into a fight, they both roll 1d6 and the highest roller deals 1 wound to the opponent. Based on that, there are some sub-rules:

- Certain items can deal more damage, add a bonus to the roll or bypass combat entirelly. That's the only way to get some kind of combat bonuses, and that's what they're for; all the focus on inventory has to pay somehow.

- Certain items can be used when there is a tie: they can from offset the tie, to win the combat straight (like, maybe, a tie in combat can represent the perfect moment to show a mirror to the medusa)

- Certain monsters can also have abilities that trigger on a tie. Unless the ability says so, the if the PC has a relevant item, the item's ability is the one that triggers instead.

- Even if there are many monsters, they count as one. Monsters only roll once per turn, but get a bonus on their roll (+0 to +5) depending on their strenght, size or numbers. This also influences the wounds that the enemy can take. Certain monsters deal more than one wound. Armor (if exists) absorbs 1 - 3 wounds.

- If many PCs confront the same enemy, only one of their rolls is taken into account, they choose which one (the highest one normally, or maybe a roll that ties to use an effect). When a monster deals damage, the party can divide it amongst them as they decide. A character that is downed is still alive, but must be tended to walk by their partners, and counts as 3 weight.

What kind of setting and adventures does this inspire? no attributes, no classes, no characters being stronger than others... Sort of a situation where all the PCs are mostly equal in capacities but with a crafting ("skill"?). If I think of items as magical compounds, I picture the titular Alchemists of this blog name. If I think of items as common items, I can see it being a game of gang kids getting in any kind of trouble armed with whatever they find available. Treasure can be anything that is relevant to the genre: from different pieces of Jewelry to the control of a neighbourhood block. And you, when you read them, what kind of game did you see in this rules?