OK, that helps.
One thing leaps to mind: if gear slots are that restricted it'd be hard to mechanically justify carrying items purely for flavour reasons only e.g. a prissy Elf that always has a complete personal-grooming kit on hand, along with his convention adventuring gear.
In a more D&D-like system using encumbrance and item weights, a character is free (or freer, anyway) to carry some non-essential lightweight gear and not be quite as deficient at dungeoneering or survival.
Well, there are some items in BitD that are light enough that they do not count toward the character's load. There's a handful for each playbook, and they are marked by italics, and are freely available. So these are essentially brought on every score, or can be. The same ruling could be applied to other items of negligible weight such as a keepsake or a grooming kit or the like.
Basically, the game doesn't really care about a character being able to carry their mother's necklace or a grooming kit from a mechanical standpoint. If those items add to the character's story, then they can have them.
The reason why I think this works is that there is enough to the system as it exists to give the player meaningful choices to make without having to rely on RP only reasons for them to make the decision.
In general, no. In specific, however, there is (to me) a big difference in perception of realism/authenticity between having three open-ended slots which anything of any weight can end up in depending on what the character needs as she goes along, and having what amounts to a pre-determined weight allowance that can be made up of any combination and-or number of pieces of gear the character (pre-)selects.
Well, it's not really items of any weight. There are some items that count as two inventory slots....such as large weapons and heavy armor, and a few others that would be pretty bulky like climbing gear. And as I mentioned above, some that do not count toward inventory at all. Most items are one slot, some are two, some are zero.
Well true, we're all going to die sometime. But unless you're getting close to that point it might as well be infinite - so if something takes three sessions to play through instead of one, so what? As long as everyone is engaged, where's the harm?
The structure of the game expects that any given session will likely consist of a downtime section, some free play, and a score. This is not absolutely required, but it's kind of the expectation.
This is likely one of the significant differences between Blades and a more traditional D&Desque game. There are specific modes of play and expectations about those modes. They can be bent or broken, but they are an assumed element of the game as designed.
And personally, I prefer that. It helps maintain forward momentum. I've had plenty of D&D games that didn't need help in that area....but I've also had plenty that needed such help.
Perhaps; but in an RPG we're not the audience, we're the characters. Bit of a difference.
Well I would say that participants in an RPG very much do serve as an audience. I just don't think their role is solely that. But certainly we are entertained by the story the game is building, right? Certainly, we can be surprised by what happens? If there isn't some aspect of being an audience, I'm not exactly sure what the point of playing would be.
Unless encumbrance rules are strictly enforced, I agree this can become a problem. Even bags of holding have limits.
Well, I would say that the encumbrance rules do try to mirror the real world to the extent that there is weight involved, and a character's strength is involved and so on.....I don't know how accurate a representation it really may be. How much can a person carry and still remain mobile enough to wade into combat? I would guess that the average inventory list for the average D&D character would likely be very limiting if we gave it much thought. A backpack alone is restrictive. Add 50' of rope and a hammer and pitons and a bedroll and waterskin and a whetstone (just in case!

) and so on.....the label "realistic" starts to break down.
I think abstracting all those weights and strength scores and the like into simple inventory boxes works just as well. Both are representing the real world fact that a person can only carry so much. So in that regard, they're appealing to the same thing, one's just more abstract.
And I can see how that would happen, certainly from an at-the-table point of view where the players have to sometimes agonize over these decisions. And from that aspect alone, it sounds great.
I guess my point is that a system like that seems to take those choices too far out of character - I'd rather see the players role-play their characters agonizing over these same decisions, maybe without as much information as they'd otherwise have.
Here's the thing....in your D&D game, what choice do the players have to make in regard to their characters' gear? Do they generally have to decide what to bring with them into a dungeon? Or is it more a case that each character has basically come up with a default inventory that they have with them at all times and it rarely if ever changes?
My experience....which I know is limited....is that it's more the second case. 90% of the characters roll around with the same gear at all times. Yes, every now and then they may be going on some specific mission where slight changes will be made. But is it agonizing to decide to bring your +1 Undead Bane Longsword versus your +2 Flaming Battleaxe just because you're expecting to face some undead?
For example, using the score again:
D&D - the character's done her research and realized she'll very likely need climbing gear, a crowbar, a towel or small blanket to muffle sounds, a bag to put the loot in, and some high-quality lockpicks - and so that (along with a small but nasty weapon and the blacked-out clothes she's wearing) is what she takes; intentionally leaving herself gobs of encumbrance headroom for all the loot she's about to steal! She gets in successfully (and in the process uses all the gear she brought other than her weapon; it turns out her research and casing were spot-on) and grabs the loot.
BitD - the character's done her research and realized there's a score to be had here, so she sets off. Being a cautious sort she decides weight be damned, I'm going 7 slots wide on this one. During the process she finds obstacles that require her to use climbing gear (slot 1), a crowbar to pry some bars loose over a window (2), a towel to muffle the sounds of the crowbar (3), her lockpicks (4), and a bag for the loot (5). She now has the loot in the bag (and thus the loot becomes part of slot 5; her weapon was in slot 6 all along).
Then just as she's making good her escape she meets a guard dog she had no previous knowledge of at all; the character looks for any sort of out-clause and (via whatever means) the GM ends up narrating that the dog looks hungry. The D&D character is likely hosed at this point as, having no idea there was a dog anywhere involved, she didn't think to bring any meat; while the BitD character, having one slot left, can simply put some meat in that slot (7), throw it to the dog, and escape.
This is the sort of thing that would bug me; that the BitD character just happens to have exactly what it needs when an unforseen or unexpected situation arises.
Obviously, had the BitD character foregone the weapon and only gone 5 slots wide the outcome would have been the same as in the D&D example, as she'd be out of slots by the time the dog showed up.
I hope you see what I'm getting at here.
Not entirely sure what you're getting at....you seem to understand the systems in a general way. The specific slots would work out differently because of the way some items are lumped together as "Burglary Gear" and so on, but for discussion, you seem to get the way the system works. Yes, in the BitD example, the character could choose to have brought some kind of food that the dog would want, and they could use that to distract the animal long enough to escape.
Why I like this is that it makes the character look competent and capable. The character's preparation as a living being in their world is not affected by my limited knowledge. To me, that's a more authentic way to portray things. The character is more capable of making decisions about the score than I am.....which makes sense to me. This is not "unforseen or unexpected" to the character.