Another AD&D second edition player and DM here!
The best version to be a DM, with such an heterogeneous set of rules...

Since PCs seem to have a peculiar sort of Diogenes Syndrome, I occasionally used them to make them get rid of junk, but it is very hard to have an exhaustive control of encumbrance, so it is better to set the encumbrance levels at guess.
No character of my group ever survived that far XD

Shit, it's been years since I last played AD&D, or some RPG indeed... Good ol' times.

I like to. I understand that most people probably don't, but to me, it feels kind of cheap if you're just allowed to pick up every piece of junk you come across and haul it around indefinitely in some unexplained manner. For one thing, it could all too easily lead to people acting like they would in an ARPG, just hoovering up everything that isn't nailed down to try to sell, instead of, you know, getting on with whatever their characters were supposed to be doing.

Besides what dtgreene said, even bags of holding have weight limits. (Or they did in 3.5, anyway.)

I find that sometimes it's better to just let people do whatever. I mean, in my experience it goes something like this - if I tell a player that he can't carry a huge barrel full of beer in his backpack, he'll immediately decide that taking it with him somehow is the most important thing ever and just will not move until he finds a way to do it. The game will grind to a halt. On the other hand if I ignore rules and common sense and just tell him "ok, you take the barrel with you" we'll just continue on with the sotry, and most likely will never even mention the barrel again.

Consequently, I only tend to really bring encumbrance into the game when I feel it really matters, like "no, you can't lift the statue up and use it as a battering ram". Same goes for stuff like food and ammunition. We always operate with the assumption that as long as the charactes have the opporunity to buy the bare necessities, they do so and we do not have to go through "we go to buy food and water" every time before they leave town.

I don't see any connection between the type of game you refer to as an ARPG and the gameplay style of picking up everything that isn't nailed down. In fact, many games that would fit that classification (which I disagree with because I don't consider them RPGs at all) don't have much that you can pick up; Crystalis and the Ys series, for example, don't have sellable junk (or any junk really) lying around. The same can be said of the Zelda series (another series that some people like to put the RPG labell on); in fact, Zelda 2 doesn't even have a currency in the first place (though it has experience points).

And that's a very sensible way to handle those sorts of things as DM. However, I'm the sort of player that would voluntarily track my own character's equipment weight down to the nearest fourth of a pound (or similar), and would argue against other PCs carrying stupidly large or unwieldy amounts of stuff around. EDIT: For example, the DM states that the PCs, looting the battlefield after an encounter, find 5 greatswords, 2 full sets of plate armor, and three suits of chainmail, as well as assorted smaller items, and one players says, "Okay, I'll take them all." My personal rule of thumb as a DM would be if you can't literally envision how, specifically, your character's carrying it, then he can't carry it.

When watching an old episode of Critical Role a couple month back, I got unreasonably incensed when one of the PCs (a gnome bard) bet his coin purse on a performance competition, then lost on purpose (seemingly having forgotten about the monetary stakes). When the NPC victor called him on his debt, he graciously handed over his pouch, which somehow contained something insane like two or three thousand gold coins. I was inwardly screaming, "YOU DID NOT HAVE TWO THOUSAND GOLD COINS IN A BELT POUCH! DO YOU KNOW HOW MUCH THAT WOULD WEIGH? DO YOU KNOW HOW LARGE THE POUCH WOULD HAVE TO BE? COINS DO NOT RESIZE THEMSELVES FOR GNOMES! THE PURSE WOULD WEIGH AS MUCH AS YOU AND BE AS LARGE AS YOUR ENTIRE TORSO!" and so on. Frankly, it would've scarcely even occurred to me as a player that I could just assume that all the money I possessed in the world (no matter how much that came to be) could be kept in one coin purse; it definitely would occur to me, however, that it would be a bad idea to have any more than some basic "walking around money" hanging where anyone could try a pickpocket/sleight of hand check on it.

I am, I guess, a detail-focused player. EDIT: But again, I can understand most people wanting to dispense with such details and focus on the important parts -- viciously killing anyone and anything who looks at them funny, shamelessly denuding corpses, tombs and occasionally entire towns of anything with even the smallest potential resale value, and, of course, making the same tired geek culture references and laughing as if they're the height of wit. :P

Also, for some reason, people seem to forget that carts and wagons exist. Until the party acquires something like a bag of holding, there's very little reason not to travel with one unless the party's venturing into a trackless swamp or a mountain range or the like.

I mostly agree with this approach, as keep the game flowing.

What I do, normally, is then try to remember (not always I succeed) weird things like this, and complicate situations accordingly.

For example (was not D&D, but the system is irrelevant): at one point, my PC found some cool piece of weaponry and armour, rusting on some dead adventurers.
They decided to pick all that junk, as they thought to fix it and resell it for a lot of pennies.
Fine. Pack everything and move along... up to when the cave grow narrow while the PCs where fleeing from some enemies.

I suddenly remember: Wow, one of the players is carrying two spears and a awl pike... somehow tied to his backpack and such. Cannot squeeze in the hole without serious repacking.

Long story short: he had to drop his backpack along much more precious equipment.
The party is much more careful now to what they pick up.

I find that often you don't actually need to do anything, just sort of imply something and let the players get a bit paranoid. You know, like if a while later I would pretend I'm checking something in my notes or in the manual and I'd ask innocently "hey, are you still carrying that barrel with you?" 9 times out of ten the player will make an "oh shit" face, expecting something like quicksand or something, and they'll say "what? no, no I ... uhm... left it at the camp! Three days ago!"

As a DM I have this unspoken rule to reward cleverness and punish stupidity. So if a player does something like that and is just begging to be robbed, they will definately get robbed. On the other if a player comes up with something creative I didn't ever think of, like a way of avoiding a trap or defeating an enemy in an unorthodox but sensible way, I'll probably let them do it even if it means bending the rules a little.

Haven't played actual D&D in so long it's as if that was someone else. I miss it and try to content myself with Temple of Elemental Evil or similar. If my life ever changes in a way that makes it possible, one of my first tasks will be to try and find a group. Meanwhile +1 to everyone in this thread.

I always thought the job of a DM was to make the game fun, not to scew the players over. Exhibit A would be one guy who would always throw NPC enemies and monsters at us that could hit our weakesses, and never get us in situations where we our strong points made us have fun cayting the day.

But this is a lost opportunity for role playing the situation IMHO ;)

I still have nightmares about "thAC0".

I guess I just like keeping the players paranoid. You know - roll the dice for no reason and go "hmmm". Ask out of the blue whether they have some skill or some equipment. Say "you don't see anything moving" in such a way as to imply it's there, but they can't see it. That sort of stuff. In my experience it's the best way to keep players really thinking about what they are doing instead of going all Leroy Jenkins.

Used injudiciously, though, it could also easily lead to players becoming overcautious, which can be just as bad.

True, only to be used in moderation. Also depends on the players. I used to do it very rarely, just to build a bit of tention when necessary. But my current gaming group is particularly gung-ho, so I use it more often to rein them in a bit.

I've always wondered if rolling a 20 against an AC -21 still counted as a critical hit or if rolling 1 even if your thac0 was 1 still counted as a critical miss.