Been scratching at this since yesterday and think Ive finally got my thoughts in order.

First:

I think this is an interesting prompt for discussion around design philosophy. Please please please do not use this as an opportunity to start drama. Bridges not explosions on this. https://twitter.com/POCGamer/status/1252707411778887680

Rules

I get why there is an impression that the OSR loves “incomplete mechanics”. There are tons of situations that are well defined in a rule set like 5e that something like Black Hack doesnt address. I think this is making some assumptions about design and play that arent true

OSR games arent rules light because they want the gm to build a bunch of new mechanics(although some gms do that). They purposefully lack specificity to encourage player creativity. They want things ill defined so that the gm can say yes. It has an added effect.

If you dont have to look up situation specific rules the game can go faster(for this style of gming. Not for everyone). Let me give an example from my own game.

One of my players had awful stats for combat. He knew he had a worse than 50% chance to hit, and he had awful hp.

The group got into a fight with some fairly nasty robed cultists in a greenhouse. So the player asked if he could light the cultists robes and the greenery on fire and then run away. The system had no rules for lighting things on fire, no fire damage, etc. so I said yes.

It made sense in the fiction, it was a clever use of an item(torch) not usually used for combat. If theyd fought by the rules of combat they would have lost. They had less hp, less damage, couldnt easily run away. So I said yes. This is by design.

The system left space for creative play by avoiding specificity. To be clear, this isnt the only type of creativity you can have in a game, its a specific type with an assumed style of gming(mechanics matching styles of gming deserves its own thread at some point).

This, by the by, is where “rulings not rules” comes from if youve heard that before.

Worldbuilding

The osr has very different ideas about worldbuilding and setting than more traditional d&d, but talks about them in similar terms. This probably causes a ton of confusion

There are some more defined settings in osr land: the hill cantons, dolmenwood. But just as often settings are implicit rather than explicit. The world matters less than the stuff in it. You get things like electric bastionland or troika.

The world is defined by classes/careers even as no street or city is named and no npcs are listed.

Worldbuilding is generative. Osr modules might give small adventures or maps to plug in to the world, but the map is largely empty until a player walks there.

There are probably some npcs, maybe some specific factions present but past that? Even the gm usually rolls to find out. You either go adventure to adventure to create the world or you generate as you go.

Its much easier to do this on an empty hex than a map with stuff, and I mean basically any stuff in it. It is far easier to generate in a blank space than fit it into a populated world.

When osr players say things like “theres not enough empty space on the map” its not really asking for an emptier map, its saying “this isnt for me”. This isnt going to be true of everyone in the scen, for what its worth, but what is?

As hinted earlier in comments, I think there is a language problem happening. We use common language starting points but between preference and shared points of reference the usage changes. Theres a hundred hundred assumptions being made in statements of fact.

And those facts are 100% correct assuming the same vantage, but we rarely share those vantages. Its like Rashomon, talking past each other assuming were talking to each other because the title card is the same. Anyway. Dont mean to wax poetic.

My hope is that this has shed some light on a different approach to gming, and clarified some things that perhaps come off as nonsensical or incompatible without context. As always, thanks for reading, keep on playing, and be kind to each other.