Running Your First Sandbox

This post is the third in a series of posts on sandbox play in TTRPGs. The first article is on why I love to play sandbox games, and the second is on why I love running them. You don’t need to read them to understand this article, but they do provide some context.

Running a sandbox campaign can be intimidating if you’ve never done it before. I was intimidated by the concept before running it myself, and I was worried that it would require too much prep to go smoothly. Once I started actually running a sandbox campaign, however, I realized that my fears were all for nothing. In fact, I found running a sandbox campaign to be even easier than other styles of play so long as I followed a few key principles.

Before we begin, I should mention that the term “sandbox” is somewhat nebulous. I recommend reading at least the start of the previous article I wrote about sandboxes to clarify what I mean by the term. In short, sandboxes in my definition mean high player agency and a living world.

There are three objectives that I use to guide my sandbox campaigns, and which helped me get into the right mindset for sandbox gaming: prepare problems (adventure hooks), embrace NPCs and Factions, and give the players a reason to care.

Prepare Problems, not Plots

The naïve approach to sandboxes, for someone used to plotted campaigns, is to prep for every possible eventuality, to be prepared for any choice the players could make. This is a herculean task, but a clever GM could limit their burden by preparing only the most likely paths (and subtly, or not so subtly, guiding the players toward these paths). If they are talented enough, or have enough time, that GM could probably even run a whole campaign by prepping in this manner. They would, also, no longer be running a sandbox at that point.

When preparing for a sandbox campaign properly, you don’t need to try to predict the players actions. First, this is because you should ask the players at the end of every session what their plans are for the next session, removing any need to guess at their intentions. More importantly though, it’s because you should be preparing problems, not plots.

For an open sandbox campaign, there is no linear story to follow, only the story that the players wish to pursue. Ideally, this story can be driven by goals set entirely by the players’ own idea and motivations. Realistically, that can be a lot of pressure to put on the players, and it helps to have a backup, for when they have no goals to pursue. This is particularly important for the beginning of a sandbox campaign, when the players likely have no idea what is going on in the setting.

Put simply, a problem is some situation in the game world that needs to be solved. This could be something small scale or simple, perhaps something that the players can solve in one or two sessions before moving on to something else. It could also be a large and complex problem, something that could take an entire campaign to solve. A good sandbox should have both, and a few of a medium size as well. Diversity of problem scale gives players a diversity of choice when deciding what to pursue.

For example, a small scale problem may be “our neighboring village stole our cattle in a raid”. This problem could be resolved in a single session of play (go get the cattle back). It may lead to other problems (when stealing back the cattle, someone in the other village is killed, and now a blood feud has started), but the immediate problem can be resolved quickly. A medium-scale problem (like the aforementioned blood feud) will likely take multiple sessions to resolve, and may simmer in the background for some time. A long scale problem may be happening in the background of this entire example, and even sparking the smaller problems. For example, perhaps the domain that these villages are part of is involved in a war, leading to higher taxes, which inspired the cattle raid in the first place.

One common way to add problems to a sandbox is to include published adventures, placing them into the sandbox to fill out space and reduce the preparation burden on the GM. This can be a great option for time-strapped GMs, but it does run the risk of reducing the sandbox to a series of disconnected adventures. When introducing outside adventure modules, take care to modify them to connect with the rest of your sandbox, by tying in goals and interests of the player characters and already established NPCs. You should also make sure that the inserted adventure has implications that matter to the rest of the setting, and not entirely self-contained. This process can occasionally be tricky, and I will try to cover it in more depth in a future blog post.

As a GM, you should only prepare the problem itself. This includes the NPCs who are involved on all sides of the problem, any locations relevant to the problem, and a brief history of what has happened so far. You should make sure there is enough information available to the players to allow them to make informed decisions about the problem. This prep does not include what happens next, however, beyond the known motivations of the NPCs involved which would guide them no matter what happens. Everything that happens next should be driven by the characters, both player characters and NPCs.

Embrace NPCs and Factions

Problems are beacons for players lost in the endless possibilities of a sandbox campaign, particularly when they are just starting out. They can give players somewhere to start, to begin interacting with the world they are playing in. Non-player characters, and the factions they are part of, are that world. At the very least, they are the most dynamic and active parts of the world. NPCs and factions help to embody the living world that is so important to sandboxes by directly responding to and forcing action from the player characters.

NPCs can serve as the causes, solutions, instigators, or victims of problems that the players face. More NPCs means that players have more options for interacting with a world, and thus more ways to solve their problems. This is particularly important for supporting sandbox play beyond a simple hexcrawl or wilderness exploration. Sandboxes can support highly social campaigns just as easily as those centered on wilderness exploration, so long as they feature dynamic NPCs.

Factions are important for long-term sandbox campaigns as a force that can drive significant change in the setting. NPCs lead and embody these factions: the faction’s motivations should be aligned with those NPCs that lead it. An entire sandbox campaign could revolve around just two adversarial factions and the interactions between them. By pursuing their own goals, factions can interrupt the plans of the player characters and advance the state of the world in parallel to the actions taken by players. They are crucial elements towards reflecting the living world that the player characters inhabit. Factions also provide player characters a potential tie into the world, which will be covered in the next section.

When building out a sandbox setting, it is important to start small. For your first session, you likely only need a 2 or 3 factions, and one or two NPCs to represent the interests of each faction. If you have the time, and you enjoy doing so, you can always create more NPCs, but you don’t need to. It is often easier to create these as you go, developing existing NPCs and adding new ones as the player characters interact with and explore the world around them.

While the number of NPCs in a sandbox campaign can balloon rather quickly, it is important to keep the number of factions manageable. To represent the living world, factions should take actions in-between sessions of play, to react to the player characters’ choices and create new problems for them to solve. Therefore, a GM should only keep track of as many factions as they can realistically manage the actions of. Individual NPCs often don’t have the power to perform great change upon the world, so you are free to create as many as necessary to fill out the world. If an NPC does have that power, it should likely be represented by a faction, such as a monarch NPC having an associated monarchy faction, to keep running the game simple.

Give Players a Reason to Care

By now, you have your problems, to give players something to latch on to, and you have NPCs and factions for them to interact with and continue driving their story. What you may not have, is a reason for the player characters to actually care about any of these things. For this, you need to work with your players.

For players to care about the problems and people of the sandbox, they must play player characters that are intrinsically tied to the world. The NPCs aren’t just NPCs: they should be the friends, family, or bitter enemies of the player characters. A player character may be motivated out of compassion or monetary reward to resolve the problems of a village they just walked into. They may just as easily decide that those problems are not their problem to solve. If this village is the one they were born into, however, it will be hard to ignore the problems afflicting it. If their character has a reason to care, the players will likely care as well.

It’s best to bind characters to the world from the very start. Encourage players to add friends and family for their characters during character creation. Involve the player characters with a faction right away, either through the characters’ backstories, or in one of your first sessions. Tie characters to a culture, and encourage players to explain what cultural norms their character adheres to or rebels against.

All of these connections between player characters and the other people of a sandbox setting give them a reason to care. Player characters that care about the world around them are necessary for driving sandbox play, especially in the long term.

Find a TTRPG That Works With You

With all of the advice provided so far, you have everything that you need to run a fun and engaging sandbox campaign. You could do this in just about any game system that you like, and ultimately the best system is the one that you and your players are excited to use. There are, however, certain TTRPGs that are better suited for sandbox play than others, and they will make running a sandbox much easier for the GM.

When evaluating TTRPGs for sandbox play, the two components I find most valuable are mechanics that allow for quick rulings on the fly and a faction system that is included, or easy to add on. As an addendum to quick mechanics, I particularly look for systems that allow an NPC to be created quickly during play.

Sandboxes enable player characters to have limitless options, and it’s important as a GM running a sandbox to use a TTRPG that supports this. Whatever path my players pursue, I want to be able to quickly understand how to adjudicate it in the system we are playing in. If they decide to go meet with an NPC that I have not prepared (which happens multiple times per session in the sandbox games I run), I need to be able to create that NPC on the fly. If their talk with that NPC goes sour and they end up in a fight, I’d also need to create that on the fly. Practically, this usually means mechanics that are relatively simple, at least on the GM side of things. Simple NPC statblocks and some sort of universal resolution system that I can default to when I’m not sure what roll to ask for are generally good signs.

There are many good factions systems available in modern RPGs, from PBTA’s Fronts to Stars Without Number’s, well, Factions, all the way up to complicated domain systems, such as in Pathfinder’s Kingmaker adventure path. Each have their pros and cons, and range from rules light, to incredibly rules dense. Which one you use is up to your preferences (mine tend towards somewhere in the middle of rules density), but using one is a crucial part of sandbox play. For many systems, particularly rules-light ones, it’s not too difficult to import a faction system from a different game, allowing you to mix and match your roleplaying ruleset with whatever faction system you like. I find, however, that the best interactions come from systems that have a faction system built in, and even intertwined with the rules of the game.

For sandboxes, I gravitate towards the OSR and NSR, and specifically games like: Worlds Without Number, Knave/Cairn/Into the Odd and all of their descendants, and any of the retroclones of D&D such as OSE and Basic Fantasy RPG. For Sci-Fi, Stars Without Number and Traveller are great options as well. Most of these games were created with sandboxes in mind, if not explicitly for sandbox play.

(Caution: self-promotion incoming!) I’ve run or played in sandbox games in many of the aforementioned TTRPGs, and have had a great time with them. I also often felt that something was missing in my games run with those systems, particularly when running sandboxes. Ultimately, this led me to create (with my co-designer!) The Years of Adventure, which was built from the ground up for the type of fantasy sandbox gaming I’ve described here. If sandbox play is of interest to you, I would encourage you to check it out.


Sandbox play can unlock a world of freedom for TTRPGs, and I would encourage anyone who has only played more linear games to give it a try. This blog post provides the basics, and should be more than enough to get a basic sandbox campaign going, but there’s a lot more to discuss on this topic.

I’ll be continuing this series of sandbox discussion on this blog, with the next post providing a guided example for setting up your first sandbox. In the meantime, however, I’d encourage you to check out some of the other excellent resources for sandbox play available for free. The Alexandrian has some excellent advice for sandbox play, such as Don’t Prep Plots, which has (obviously) had some influence on this article. Worlds Without Number and Stars Without Number by Kevin Crawford have great advice for sandbox play (they gave me the confidence to run my first sandbox campaign), and they are totally free!