The baseline Dungeons & Dragons game offers player characters plenty of chances to gain treasure and few chances to spend it.

When Dave Arneson opened the dungeons beneath Castle Blackmoor, Chainmail miniature battles served as a game within his game of dungeon crawling (or technically vice versa). Player characters spent gold to raise armies, launch fleets, and build castles.

Since then, various rules for clashing armies have complimented D&D’s editions. For more, see Dungeoneering and the Art of War by Shannon Appelcline. Few D&D players care to trade their characters’ adventures for a miniature wargame, so none of these war games within D&D lasted. Without the miniature game, PCs could still buy strongholds, but their clubhouses entered play about as much as a fancy hat drawn in a character portrait. Some players happily feather their characters’ caps, but most players will not chase simple trophies.

Instead, players favor investments that factor into play. Magic items affect the game’s core of adventuring, so they make a popular way to spend. To create a campaign where players eagerly spend on more than magic, expand the campaign’s scope beyond dungeon crawling and dragon slaying. Follow Dave Arneson and add a game within the game.

If you want to create a war game within your campaign, fifth edition D&D offers a set of mass-combat rules. The spirits of Dave and Gary will smile down on you as you play D&D as they always intended.

However, unless your group features a rare bunch of grognards, you probably need a secondary game that better suits roleplayers.

In this post, I review some history of the game within the D&D campaign and show how the story leads to 5 lessons.

D&D expands beyond fighting men

When D&D grew, many new classes did not suit the original goal of building castles and commanding armies. Perhaps thieves could build a hideout, but druids could only plant a tree. The original, stronghold-building game unraveled.

Lesson 1: The game within a game must match the players’ characters and their goals.

You need not tailor a game for each character, although you can. As a dungeon master, when you start a campaign, you can establish a goal for it. For example, the PCs must fight to free their homeland or scheme to raise a princess to the throne against her rivals and their shadowy supporters. The players can decide how their characters come to share the campaign goal, but they all need a reason to join together and work toward that goal.

A game within the D&D campaign should let players advance their characters’ goals.

D&D Companion Rules

The best attempt at a game within a game came when Frank Mentzer wrote the D&D Companion Rules (1984), supporting play from levels 15 through 25. These rules included Dominion rules to drag the PCs’ strongholds into the game. The rules give players something to do with their domains, even if it’s mostly bookkeeping.

PCs start with a county, build a castle, and watch its population and economy grow. Players do the calculations. When I read the rules, I admired the design, but the activity seemed colorless. The dominion rules seem like tending an aquarium, with more paperwork.

Lesson 2: Losing must seem possible.

Now imagine that the PCs hold a dominion at the last bastion on a hostile border. Imagine the PCs defending their subjects with shrewd administration, diplomacy, and typical PC heroics. This dominion game becomes compelling. Once defeat seems possible, the dominion turns from a bookkeeping activity into a game.

D&D War Machine rules

The D&D Companion Rules also included a War Machine mass-combat system that let players resolve battles without building a basement sand table. “To use the system, all you need is a pencil and paper, plus some knowledge of simple arithmetic.”

Lesson 3: The game within a game typically must to be simple, because the players sat to play D&D .

Traditionally, adding mass combat to a D&D campaign meant adopting another game—almost another hobby. When Frank Mentzer and Douglas Niles created the War Machine mass combat system, they made a key insight: For their game within D&D to work, it needed to be simple enough not to distract from the usual D&D adventures. If anything, War Machine brings too much realism. Most D&D players would happily adopt something as simple as the Risk rules.

Lesson 4: Players must see how their choices will lead to outcomes.

The pursuit of a simple rules might tempt you to reduce the game within a game to DM fiat. Instead of inventing some simple rules, you just rule on an outcome. Don’t make this mistake. Relying on DM fiat will rob the players of their agency: their sense that they control their destiny in the game. Players will wonder if your ruling just follows whatever narrative you dreamed up at the start.

Instead, the players should understand understand the rules of the secondary game well enough to plot strategy. They should know how their bribes will affect diplomacy rolls, and how the mercenaries they hire will swing the battle.

Battle Interactives and Epics

Some of my favorite games within a D&D game only spanned a single session: the convention games known as Battle Interactives or Epics. These games gather hundreds of D&D players into a ballroom, where they cooperate to reach a common objective. While players at each table race to win battles, the event’s organizers create a game within the game to track progress toward winning—or losing—the war. For more, see “Living Forgotten Realms Battle Interactive.”

These events work best when the organizers use a projector to display progress: battles won and lost, territories claimed, and so on. The players may not know the rules of the game within the game, but they see how its outcome turns on their actions.

Lesson 5: Show players their progress toward success.

Good games within a game tend to focus on a game board. This board might show provinces freed from the dread emperor’s rule, or it could just list electors and show their willingness to support the princess’s claim to the throne.

Advantage

In the typical D&D game, PCs wander the game world, looking for troublemakers to kill while increasing their battle prowess.

The game within a game helps transform your game world from a backdrop to something vibrant. It can transform PCs from drifters into people with a home. PCs can use their wealth to extend influence and change the world—and not just by murdering the troublemakers.

Disadvantage

Even the simplest game within a game demands a lot of work. Some players just want to slay monsters.

Next: In fifth-edition D&D, what is gold for? The cash-poor, big-score campaign