A specific philosophy of play underlies the core rules, so in this section we outline that philosophy so that you have a better understanding of the purpose of play in an OSR+ game. We will compare OSR+ to traditional games as well as two popular movements in the indie RPG design space: that of the old school revival itself, and that of games coming out of the Powered by the Apocalypse (PbtA) tradition.
It's important to understand how OSR+ is designed in order to use its mechanics to their full effect. Moreover, OSR+ encourages you to DIY the game to suit your purposes, both when designing adventures and making rulings. Understanding the design intent behind the game will help you make fairer, more efficient decisions as you go about doing this.
In designing OSR+, the goal was to create a game where the basic rules set was simple enough that people who'd never played tabletop RPGs before could grok the rules as they played. We wanted to create a system that makes sense intuitively and doesn't ask a lot of people's short term memory, so that players can focus on inhabiting their characters and remain immersed in an emergent narrative without worrying too much about the mechanics. And on the GM side, we wanted the game to involve easy prep that gets out of the way when designing adventures.
But central to all these goals was the question of why the game is played at all.
We all come to RPGs for different reasons, and everyone's reason for playing is valid unto itself. OSR+ is designed with a very specific purpose of play in mind: we want to fulfill the narrative ambitions of our heroes. We're not "playing to find out," per se, although that certainly will happen in the course of play: we're playing to fulfill our heroes' destinies, whether that's to fulfill a sacred oath to a long dead god, track down the nemesis who kidnapped our daughter, or destroy the dark artifact that poisoned our homeland. OSR+ requires the GM and players to collaborate, through session zero, in seeding the adventure with story hooks that make those sort of narratives "playable." This concept sits at the heart of the game. If there's anything you should come away with from this game master's guide, it's this.
Write What You Know
We didn't set out to reinvent the wheel with OSR+.
The game uses all the same basic concepts we're familiar with in many other RPGs: hit points, attribute scores, initiative, skills, metanarrative currencies like tags and bennies, etc. We deliberately set out to name things in the least pretentious way possible, divorced from any assumptions about lore or campaign settings, so that anyone who's ever played any sort of fantasy game before would immediately know what we're dealing with.
OSR+ borrows heavily from other old school style games like Warrior, Rogue, Mage by Stargazer Games to simplify the system's attributes to three basic stats (Mighty, Deft, Smart), and incorporates ideas from Wonders & Wickedness and Marvels & Malisons by Lost Pages to simplify the magic system. In creating OSR+, we pored over, cataloged, categorized, and cross-referenced the meat of too many old school games to acknowledge here, and stole metacurrencies and "fiction-first" techniques from PbtA gems to make things like conflicts, flaws, and ethos mechanically meaningful to the game.
While OSR+ is still largely simulationist in its approach to mechanics, its hat tip to the PbtA tradition allows players limited freedom to grab the dials of the narrative and steer the fiction toward their heroes' destinies. The result is a game that allows for satisfyingly orchestrated cinematic moments without sacrificing that (optional) old school crunch many of us grew up with.