How Does a 5E DM Get Started With OSR Games? : Part 1: The Key Concept

I’ve been seeing evidence that there are more 5E DM’s becoming aware of the OSR.

Recently there have been a lot of questions on the /osr Reddit and videos on YouTube from folks who have recently discovered the Old School Renaissance, and are OSR curious.

I don’t know what the catalyst for that is and I’m not going to speculate. If you are a gamer that has only played more recent versions of the “world’s greatest role playing game” and are now interested in learning about the Old School Renaissance, I’d love to hear about what inspired you in the comments or a private email on my contact page.

A lot of the answers to the question of “How do I get started with the Old School Renaissance,” I see on Reddit and elsewhere start with which games you should check out. Sometimes there will be game and adventure module recommendations. Other times you’ll see recommendations about some seminal blog posts or essays.

I have a multi-part response starting with this blog post.

A lot of game masters picking up an OSR game believe that the rule set is the number one difference between WotC published versions of D&D and Old School Renaissance. The number of hit points, the spells that magic users get, XP for GP, race as class, and so forth.

I disagree.

There are several blog posts about how you can play 5E in an old school style and use the optional rules in the DMG to make it more old school. While I think it is optimal to play an OSR game system, you can play 5E in an old school way. That leads us to an important question.

If you can play 5E “old school” then what’s the difference?

Caveats and nuance.

This essay is for tabletop RPG hobbyists who are familiar with contemporary tabletop role-playing games but would like to try out Old School Renaissance games. I enjoy OSR games and hope to teach you what I see as an often unstated underlying premise of OSR games so that you might enjoy them as well.

I am not “shoulding” on you. This post is a description of what I think someone who is new to Old School Renaissance games needs to know to get the best experience of the games and play style associated with it.

I am telling you what I think is the fundamental design intent of most of the OSR games even though many (maybe most) OSR designers or game masters might not use the terminology I’m about to lay out.

What I’m describing below is what I see as the general tendency. Though I sometime write in a definitive, “this is how it is” voice, these descriptions aren’t absolute.

There are some old school game masters and designers who, in my opinion, have very “new school” approaches to rule sets. In some ways, I feel the impetus behind Advanced Dungeons and Dragons had the seeds of “new school” D&D in it.

Yes, I know, heresy.

There are some games that are considered “new” but have a lot of “old school” thinking in them. Games being published by Modiphius and Free League have a great deal of “old school” mindset.

I would like better terms than “old school” and “new school.” Allow me to disabuse the inquirer that I desire innovatory classifications as a pedantic exercise for the academically minded to publish dissertations debating the relative merits of problematic semantics in obscure journals contemplating ludonarrative implementations.

It would be nice if we had a practical set of tools to use when marketing, buying, designing or running games that were more descriptive than “old” and “new.”

One thing I learned from reading The Elusive Shift by Jon Peterson is that a lot of ideas gamers in 2022 think of as “new” were discussed and debated in the ‘zines of the 70’s and early 80’s.

Games from the 70s that are out of print and forgotten have designs and mechanisms that your most Indie of Indie designers would think are new and innovative if all you did was slap on some weird illustrations, freshen up the text, and drop it on That revelation makes it a lot harder for me to say this game is “new” that one is “old” and for it to mean anything in reality.

The OSR is varied, means different things to different people, and has largely become a label that applies to a general class of games that seem wildly different to the uninitiated.

I think what makes an OSR game an OSR game is that they are built around a key insight that Dave Arneson and Dave Wesley discovered in their experiments with wargames. This basic design intent is employed in a way that many (if not most) contemporary game designs have moved away from. That’s what I’ll be describing in this essay.

The basic parts of an RPG.

There are three fundamental pieces to a tabletop role-playing game.

All three of these pieces are required.

  1. The Contextual Framework (The setting of the game)
  2. The Closed System (The rules)
  3. The Open System (The stuff in the GM and Player’s head)

All three pieces interact with each other in ways that are complex and dynamic.

The Setting is made up of the fictional places, the non-player characters, objects, concepts and narratives that make up the contextual model of the game world.

In order for players to create a mental image about who the characters they are playing, the world their characters inhabit, the types of creatures, gods, places, cultures; there has to be a “world” for them to play in. The setting provides context.

The Rules, or “closed system” if you prefer, are the fixed rules that govern specific and defined events in the game. These are the rules that are set out and agreed on before the game starts.

While rules can be alterable in tabletop role-playing games, we do use a set of agreed upon rules and we don’t typically change them in the middle of play. For circumstances that are clearly defined in the rule set and match the criteria happening in the game, we use the closed system of the rules. The closed system of the rules allows only specific actions and specific possible outcomes.

In classic adventure games, combat and exploration procedures are the bulk of the rules.

The Open System is the stuff you bring to the table in your head and use to manipulate the setting.

It is the books you’ve read, the films you’ve watched, your memories of the camping trip you took with your friends after college, the picture book about castles you looked at when you were 12, that Iron Maiden song you like… It is what you bring to the game that isn’t part of the setting or the rules before you got there.

The open system was the key discovery made by Dave Wesley and led directly to Dave Arneson’s creation of Blackmoor. I don’t think they defined it the way I’m going to describe it. I do think they understood that this was the thing that made their games different from most other wargames.

There is no such thing as a tabletop role-playing game without the open system.

Take out the open system and you have a dice game, card game, a board game, or a computer game.

The game can have a setting and even a narrative but if you cannot alter the state of the game in a way not described by the rules or informed by the setting material provided by the game master or designer then you don’t have a tabletop role-playing game.

The open system is the key to understanding OSR games.

If you don’t get this, you will have a hard time understanding how OSR games work.

In OSR games, the open system is given priority and emphasis. In all versions of D&D published by Wizards of the Coast, the closed system is given priority and emphasis. In a 2009 interview, Skip Williams, one of the primary designers for 3rd edition D&D lays out the intent.

The early designers were wrong. It comes down to this: If you want to be in control of your character, you have to have some idea how anything you might try is going to come out. and you can’t know that unless you have some idea of how the rules are going to handle the situation. If the GM is making capricious decisions about what happens in the game, you’re always shooting in the dark and you have no real control over your character at all. Think of how hard it would be to, say, learn to ride a bicycle if the laws of physics were constantly in flux. The game just works better if the DM and players have similar expectations about how the rules handle things.

Skip Williams in a Grognardia interview.

While Skip has a valid point, many of us who prefer OSR games don’t want more rules.

3rd edition discouraged the open system and limits its use, as the quote from Skip Williams indicates.

4th edition was a game that nearly eliminated the open system, which is probably why it is all but dead. 4E was a miniatures skirmish game + board game with a narrative connecting the battles. Kind of like a porn flick, the narrative was in service of the action and not the other way around.

Mike Mearls took 5E back toward the old school preference for the open system but not quite as far as the OSR does.

As Mr. Williams suggests; adverserial, capricious, egomaniacs make for bad game masters and miserable gaming.

My solution to the problem of capricious game masters isn’t more rules. My solution is clear and open communication about expectations, and (most importantly) a culture of trust and collaboration between game masters and their players.

This is a preference that even the most extreme camps of the OSR scene agree about.

We don’t want more rules. We want to be better game masters and play with better game masters.

This approach is not easy. Sometimes it totally fails.

It isn’t a perfect solution but neither is a thick tome of rules.

The open system is like air; critical and invisible.

The open system is almost invisible. We are birds flying in the air of the open system.

The open system typically isn’t explained or described in game rules or the ubiquitous “What is a role-playing game” section of core rule books. Many game masters aren’t conscious of it. It is assumed that this is how you play the game and everyone knows that. It doesn’t require explanation.

You will often see the open system described as using your creativity and imagination which isn’t particularly helpful for someone who has never experienced this style of play.

Many designers assume that you are going to be introduced to the game via playing with another group but that has gone away. According to marketing at Wizards of the Coast, more players are learning 5E via YouTube than the old way of playing with an established group.

It is true that the best way to “get” the way OSR games are played is to play them with a good game master. I find that it is much easier to show a player how this works than explaining it.

Once a new player gets that they can attempt anything even if it isn’t in the rules, the lightbulb goes off and they run with it. It’s why I prefer to play with people who have never played an RPG over people who have only played “new school” RPGs. I don’t have to deprogram them from looking at their character sheet all the time.

Even though it is easier to show you what the open system is, I’m going to attempt to explain it so you that you can watch an actual play video and recognize it.

What does it mean for a tabletop role-playing game to emphasize the open system?

Old School Renaissance games emphasize the open system in combination with the setting of the game and limits the intrusion of the rule set as much as possible.

Tabletop roleplaying games are a series of problems player characters overcome to achieve a series of objectives. Many times several smaller objectives must be achieved before the main problem of the adventure scenario can be overcome.

In a classic dungeon crawl, the players must overcome the problems of light, movement, monsters, traps, managing resources to achieve the ultimate goal of clearing the dungeon and removing its treasures. Other games require players to overcome the problems of finding clues, figuring out how they fit together, and then defeating the threat to the status quo.

Players ask questions about the situation and the environment their characters are in and use the information provided by the game master to produce a solution to that problem. Sometimes they use the closed systems of the game. Sometimes they use knowledge they have about the setting. Sometimes they use their general knowledge of our universe, life experiences, or common sense to solve the problem they are facing.

In OSR games, the primary tools players are encouraged to use is their understanding of the the setting and the open system (the stuff in their head).

Most of the play in an OSR game consists of dialogue between all of the participants without reference to rules or procedures of the game. That doesn’t mean they don’t use the game’s mechanics. It means that it isn’t the focus of the game.

Most of the dialogue is a description of what the player characters are experiencing through their senses and the way they respond to those experiences in natural language without references to the rules and procedures of the game.

The GM typically will not say “make a search check” when players say they want to search for a secret door or trap. The GM will often roll the die and tell the players what their character sees without any reference to the result of the die or the rules and procedures being employed. They are being used, but no overt reference is being made to them.

The open system as problem solving and resolution tool.

As OSR games tend to be played, the open system is encouraged both as problem solving tool for players and the resolution tool for game masters.

Many OSR game texts describe the open system as the maxim “rulings not rules.” Game master fiat and open system are often conflated but they aren’t quite the same thing. GM fiat is part of the open system but the open system is more than that.

The open system is the player utilizing their personal knowledge, experience, and creativity to solve problems in the game. Rather than using something that appears on their character sheet, a player may take knowledge of our world and apply it in a way that makes sense to them in the situation.

The open system is also the referee utilizing their personal knowledge, experience, and creativity to resolve situations not covered by the rules. When players come up with a novel solution to a problem their characters face the referee can use their knowledge of our world to adjudicate the outcome of the player’s decisions.

If the players say, “I want to do X” and if “X” is an action for which there is no explicit rule and the game master thinks the player character can accomplish, it simply happens. No die roll or reference to a rule is required.

An example…

Situation: The PCs are traveling through a forest on their way to a dungeon. The ranger came across a deer carcass as he was scouting the area around the trail they are taking through the forest.

Game Master: You’ve been traveling all day and it will be dark in a few hours. What do you do?

Ranger: Don’t forget the deer partly consumed by wolves a mile back. The tracks were about 8 hours old. The wolves may still be in the area.

Fighter: Lets stop and camp. I’ll gather wood and make a fire to discourage the wolves from coming into our camp.

Magic User: I need some sleep so I can reset my spells. Don’t wake me up unless you are all going to die.

Cleric: I’ll take the last watch.

Game Master: Darkness falls. Thud. You see the red glow of eyes reflected in the dark but they keep their distance.

I think it is instructive to break this down into its parts.

The characters are traveling through a forest. There are mechanisms for rate of travel, how far you can see in any direction, whether a ranger will notice the carcass and what information he can glean from it. None of that is mentioned.

The only thing the DM told them was the ranger saw a carcass, that wolves had eaten it and they were there about 8 hours ago.

The fighter makes a fire and GM decides the wolves make themselves known but keep away. There isn’t a mechanic for either of those things in most OSR games. You might use a 2d6 reaction roll with a modifier but there’s not specific direction for this situation in any book I’ve read.

Forests, obviously, are concentrations of mature trees. Does the rule book define a forest? Probably not. It assumes that players bring that knowledge in their head to the game.

Trees drop dead limbs. Those limbs lay on the ground in the forest. They are flammable. Again, the game designer and game master assumes we know this. There are no rules in the book for how long you have to spend gathering wood, how much wood you need, the species of trees in the forest etc.

The game master assumes that the player characters know how to start a fire and keep it going. The GM decides that since the wolves have had a meal just this morning, they aren’t hungry enough to attack a party of adventures with a fire (something wild animals tend to fear) and keep their distance.

The player uses their knowledge of wild animals, forests, and campfires to solve the problem of the wolves. The ranger could use the tracking mechanism of the game to follow the wolves, and the combat mechanisms of the game to fight the wolves. Instead the player uses the open system in combination with the setting information (there’s a forest with wolves) to solve the problem and the mechanisms of the game never come into play.

The Triple Threat

I am not saying the closed system of the rules is not important. Nor am I saying they aren’t used and we are merely playing “lets pretend.” That is a different sort of activity. We are playing a game with a closed rule set as part of the system. The rules, the setting, and the open system work together to make the complete game.

Players and referees combine setting knowledge, mastery of the game mechanics, and their real world knowledge. This is the magic of tabletop role-playing games.

My favorite moments of play is when my group comes up with outrageous “What if,” scenarios. They take setting knowledge, rules knowledge, and use the open system to come up with entertaining solutions to sticky problems.

What if I snuck into the army camp using the ring of invisibility, set some donkeys on fire with the greek fire and cut them loose?

The Mushroom God wants an offering of corpses in exchange for fighting on our side against the Gith. What if we animated corpses of the Gith we kill and march them back here as the offering?

I bet there is some nasty demon trapped in this iron flask we stole from those Einherjar. What if I opened it in the crowded plaza of the demi-god’s worshipers?

The combo of the three systems means a player can do almost anything they want given that…

  1. It fits the context of the setting.
  2. It doesn’t break the rules.
  3. The game master and players agree that what the player wants to do has some chance of succeeding.

Clear as mud?

I hope this long essay was helpful to you.

My knowledge of game design and serious game theory is limited. There is probably some obscure paper or text that I’m not aware of that explains this concept better than I have. If you know of something, please drop a comment below. I’m always looking to level up.

The next post on this topic of “Getting started in the OSR” Will be more about what games are out there, and how you might go about picking one to try with your friends.

9 thoughts on “How Does a 5E DM Get Started With OSR Games? : Part 1: The Key Concept

  1. Vidgrip

    Spot-on. This is a great explanation for those who have only played 5e. It is also good food-for-thought for those who view a highly mechanistic 1e campaign as the pinnacle of old-school play.

    Liked by 2 people

  2. Daniel

    This needs to be on a t-shirt:

    “Allow me to disabuse the inquirer that I desire innovatory classifications as a pedantic exercise for the academically minded to publish dissertations debating the relative merits of problematic semantics in obscure journals contemplating ludonarrative implementations.’

    Liked by 1 person

  3. Daniel

    I like this a lot. I’m a 5e DM and tho I really enjoy 5e, I love a lot of the detail and ascetic I am seeing in OSR games and want to bring them into my campaign. I am a little confused by your example tho – the way you described it was exactly how it would happen in my 5e game.

    I think there is an interest branching happening in 5e – one side is moving towards “less rules – more options” (like OSR/indie games) and the other side to “more rules – more options” (like here are 5 different types of spear, each with different stats! Plus new rules on how to attack each different body part, in a casual, forceful or aggressive manner!).

    I’m definitely on the “less rules – more options” side BUT I like a lot of classes/subclasses and non-LOTR fanfic races so I guess I’m in the middle.

    Liked by 1 person

    1. IMO, the key part to OSR-style character creation isn’t that there aren’t Tieflings or Genasi or Half-Weretigers or whatever – you actually see lots of very wacky homebrew classes in the scene. The key part instead is that character creation is quick, so you the player don’t feel like you lost out on an irrevocable investment when they die.

      (I actually wouldn’t even say that high lethality is an important aspect in itself – but that if the conceit of the fiction is that characters are venturing into situations where death is a distinct possibility, then death should in fact be a distinct possibility.)

      If the example rings true to you, then I think you’re right that there’s tremendous bifurcation in terms of how people run 5e. My IRL group shifts DMs quite a bit, and while we largely stick with 5e because it’s what everybody knows, you get a lot of variation in how often DMs ask for people to roll the dice.


  4. Paul

    This is one of the clearest explanations of RPG design that I’ve seen. It’s ironic, as you noted, that so many narrative style games have appeared in the last decade, which probably would have been right at home in the early days of the hobby. In some ways, games like PbtA evolved on the open system while D&D/PF evolved on the closed system. It’s great to be around in a time where there’s so much variety to choose from.

    Liked by 1 person

  5. Pingback: Getting Started With The OSR: Part 3: Put Story In Its Proper Place – Grumpy Wizard

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