Maxperson
Morkus from Orkus
He didn't say they can't know anything of the world until informed. He said what he wanted might not be available. If I play in his world, I know swords exist before I ever start the first session. I can add a sword to my shopping list. When I get to town, though, there may not be a sword for sale. There not being one for sale isn't the same as not knowing whether swords exist within the world until told.If you agree that you cannot know anything of what is in the world, not even in principle until the GM has undertaken efforts to inform you, then how can you possibly have a "shopping list" prior to that?
Like you're literally undercutting your own message here!
The same goes for everything that is D&D standard or extends logically from that. If anything non-standard is happening, like the world has no swords for some reason, the DM will usually let the players know that prior to play. And rarely, you might be wrong when you assume a logical extension from something D&D standard, because strange things are sometimes present in settings that would keep it from happening.