The Sale guide is great, thanks! Do you know of something similar but for core rules? Current or past.
I'm repeating my answer to him below. I assumed they are already familiar with all the major retroclones and original games, therefore I focused on a bit more “exotic” recommendations:
The Majestic Fantasy RPG. An OD&D game based on Swords & Wizardry Core. Interesting mix of many different things based on several decades of play.
Tekumel: Empire of the Petal Throne. The original was built on OD&D chasis. I don't run it as-is, but rather use it for inspiration (e.g., early skill system, interesting take on fighters, etc).
Adventures Dark and Deep CoreRulebook & Bestiary. An alternative imagining of what AD&D 2E might have been if Gary remained in control. A lot of classic, but good stuff.
DriveThruRPG is running a big sale until end of July. There are few special items that are 75% off, but most are around 30% off.
Here are twelve big-ticket items where discounts make the most difference:
Original Adventures Reincarnated #7: Dark Tower (5E or DCC version). A three-book set reviving an old classic by Jaquays. Worth getting it just for the original.
The Northlands Saga Complete. a compilation of ten adventures set in stereotypical cold north. Probably enough for several years of gaming. Tenfootpole has reviewed first four adventures back in the day (NS1, NS2, NS3, NS4).
Classic Gaming Negative Space print bundle. Includes On Downtime and Demesnes, Artifices, Deceptions, & Dilemmas, and Bestial Ecosystems Created by Monstrous Inhabitation trilogy covering downtime, environs, and monstrous ecosystems.
Majestic Fantasy Realms by Robert Conley, the spiritual successor to the Wilderlands of High Fantasy, is launching soon on Kickstarter. It is a sandbox fantasy setting perfect for hexcrawl games.
Crowdfunding campaign will include:
Setting guidebook
5 Judge maps (12” by 18”)
5 Player maps (12” by 18”)
Rob will be releasing the whole setting under Creative Commons so anyone can adapt, modify, and contribute to their desire.
You can learn more about the setting on Rob's blog, and sign up to be notified upon launch at Kickstarter.
OSRIC, Old School Reference and Index Compilation, was the first retroclone of Advanced Dungeons & Dragons. Released almost 20 years ago, it led the charge during early days of OSR, providing means to legally publish content compatible with AD&D.
OSRIC 3.0, brings a host of improvements, focusing on providing more explanations and examples of play, replacing dense blocks of text with more accessible layout, discards OGL, brings the rules even closer to AD&D, just to name a few.
Campaign includes:
Player Guide (hardback smyth-sewn, landscape orientation)