The quantity and quality of some of this stuff everyone posted is amazing, I've read and printed ton of it.
I found this rather useful. How To Get Started Playing Old-School D&D For Free:
https://dungeonspossums.blogspot.com...-school-d.html
This is pure gold, amount of additional links and content is awesome.
Matt Finch's A Quick Primer on Old School Gaming - great for someone who has a little or no clue about OSR, for me
Principia Apocrypha seemed better.
estar - sir, the material about Sandbox creation and blog is great, added to favourites.
If you started out with AD&D 2E you aren't that far from the right place already.
Maybe, but just after the fall of socialism/communism in Poland role playing games were something extremely rare and niche, so when we discovered them we had no clue about how to play. We only could reference them to some games like Betrayal at Krondor and we were simulating stories. It was great, but far from what it was meant to be played. Then came 3rd edition of D&D which pushed away from old-school approach, so me & my group in Poland are noobs when it comes to old school and sandbox despite having over 20 years of gaming under our belts. But we are looking forward to it. After playing some 5th edition we came to conclusion it is so full of unimportant choices, it is so hard to die there and so easy to replace everything with a dice roll it's far from our tastes. And we started digging. Now we're playing Astonishing Swordsmen and Sorcerers of Hyperborea but already looking forward t buying and running more OSR systems.
Thanks everyone for great posts, I won't hesitate to post some insight or questions. I think I need to perform some kind of briefing to my players and tell them what's gonna be different in our playing style because they have the same amount of assumptions as I do I guess. The mentioned Principia Apocrypha has special section "for players" with some great advice.