Last week’s Unearthed Arcana covered Mass Combat for the second time since the series launched at the beginning of Dungeons & Dragons 5th Edition. Behind only the Ranger class, it is the second most-covered subject of the series, meaning D&D’s designers feel there is a gap in players’ expectations and the rules as written.

Frankly, I don’t care much for either entry, as both sets of rules offer too much unnecessary crunch to a game that’s elegant and streamlined. I don’t have any particular gripe with the rules they’ve presented (though they’re more complicated than just using a swarm, for no real benefit), but rather with the fact that any rules are presented at all. Simply put: most RPGs, including D&D, don’t need them. However, this latest Unearthed Arcana does capture the most important element for running exciting mass combats, buried in the very final section: Critical Events. An RPG should focus on the moments where the characters’ actions influence the direction of the story most, and these inflection points–Critical Events, in the parlance of the UA article–should be the point of focus for the rules and the Gamemaster.

To illustrate this thesis, think of the Trojan War. It’s a story that has been retold a thousand times, but can you recall anything about troop formations or the tide of the broad battle at any given point? The Greeks attacked and the Trojans held firm. Alternatively, think of the battle between Hector and Patroclus; Hector famously slew Patroclus, believing he was Achilles for he had donned Achilles’ armor. Achilles, on learning of Patroclus’ demise, entered the battle in earnest and turned the tide in the Greeks’ favor. More to the point, if you were retelling the story at a tabletop, would you rather focus attention on the minute movements and formations of the regular Greeks and Trojans, or on the epic duel that led to the entry of the Greek’s greatest champion and, ultimately, the demise of Troy? To borrow from the silver screen, would you rather focus on the naval battle around the Second Death Star, or the Millennium Falcon’s bombing run into its core?

Setting up Mass Combat for Critical Events

Though we reject the idea that an RPG need give attention to the minutiae of combat on the broad scale of an army, we still need to establish the events of the mass combat as a backdrop for the Critical Events. I use a simple step-by-step process which turns the battle into a series of rounds, with the rounds defined by changes to the steady-state of the conflict, rather than fixed periods of time. Based on the flow of the session at the table, decide how to weight each step on an axis of mechanical-to-narrative resolution.

Establish the steady-state of the conflict Allow the PCs to intervene Determine the consequences of intervention Repeat

1. Establish the steady-state of the conflict

The steady-state is the most likely outcome barring any extraordinary intervention from the player characters. In some rounds, this will be the enemy’s bold strategic move to win the battle which the PCs must counter. In other rounds, this will be the steady attrition of the conflict that prompts the PCs to reverse the tide. It can also simply be the fortunes of war turning against them, with famine or disease striking their ranks unexpectedly.

The key for this step is to push the PCs from passive observation to action. They must understand that if they do nothing, they will face additional challenges and, ultimately, will likely lose. Narrate this information from in-game sources, such as reports from the spies and scouts, rumors spreading amongst the troops in the trenches, the grumbling of the regiments recently rotated off the front line, or the PCs’ own observations, rather than from an omniscient narrator, as this helps to build immersion and introduces an element of doubt.

2. Allow the PCs to intervene

Once the PCs understand the lay of the land and understand the risk of losing the battle, they should figure out their approach to intervention. This may be as simple as a strategic counter, such as deploying reserve troops to the western flank, or retreating from the eastern lowlands to more defensible positions on the nearside of the river. In that case, you may not need mechanical arbitration, and can simply narrate the outcome and its impact on the steady-state.

Other times, the PCs propose a risky mission, such as assassinating an enemy general, sabotaging the construction of a dangerous siege engine, or seeking out a neutral third-party and convincing them to intervene on the PCs’ behalf. In these cases, drill down into the details of the critical event based on the importance to the overall story of the battle. If assassinating the orc Warlord Rumkala is a surefire way to end the orcish invasion, then it should be an adventure in its own right, lasting a full session or even multiple sessions as the PCs scout, infiltrate, and attack the Warlord and his honor guard. Conversely, if finding and stopping the saboteur who is poisoning their water supplies simply allows them to fight on equal footing, resolving that critical event might require a couple of encounters and half a session.

3. Determine the consequences of intervention

Once you understand what the critical event is and how the PCs carried it out, determine the consequences of those actions and how they impact the steady-state of the battle. Keep in mind that this isn’t necessarily a binary resolution; they may have faced multiple challenges in the previous steady-state, and only addressed one of them. Likewise, if they faced a single threat, but only achieved a partial–or even pyrrhic–victory in their mission to intervene, the threat may evolve and continue to press upon them.

Depending on the nature of the critical event, you may wish to introduce randomness to the outcome. While the Unearthed Arcana article provides a series of mechanics for extrapolating relative strength of units within an army, including combat prowess, leadership, and morale, I find this typically works fine with a less scientific approach. Simply estimate the odds of success for the PC’s side, and roll a die (a d10 makes for nice 10% increments, while a d20 gives 5% increments.) For example, if the PCs have reinforced the weakened left flank, you might decide that their allies had a 30% chance of success before reinforcements arrive, but with reinforcement their odds are improved to 70%. Roll a d10, and on a 7 or lower, the flank fails to hold. These round numbers narratively represent the difference in combat strength between the enemy ogre shock troops and the human pikemen, the defensive advantages granted by the terrain, the tactical prowess of the human field commanders, the shaky morale of the human troops, and the tendency of the ogres to fight amongst themselves in pursuit of maximum glory. Simply put, use the narration to justify the numbers, rather than relying on the numbers to simulate your narration.

Once you determine what this outcome looks like, narrate it and repeat the process to begin the next round. There should be new threats as the enemies respond to their defeat or press their advantage, inviting new interventions and additional critical events for the PCs.

4. Ending a battle

Whether the battle ends in a few hours or a few years, eventually the GM must break the cycle and return to the more normal, character-focused narrative structure. Often, I find the flow of the narrative itself informs this decision, as it has begun to tilt heavily in one side’s favor. If that’s the case, simply declare that the battle has ended, and return to the normal narrative. Alternatively, you can track the battle on a sliding scale, with a side needing to push the scale a certain number of critical even victories in their favor in order to win. Though a mechanical measure can be satisfying, keep an eye on your players’ enjoyment of the narrative arc; if their interest in the conflict is waning, you may wish to end it prematurely.

Regardless of how you determine the winner, there are plenty of loose ends to tie up for the PCs when they’ve been involved in a large-scale battle. If the PC’s side has lost, make it clear that there is little possible in the way of intervention, as their side is broken; they lack the troops or supplies to fight, the alliances that formed their army have sundered, or their leadership has surrendered. If they have won, there are spoils of war to divvy up, enemy champions to pursue, social problems to address, or even opportunists who wish to betray them now that the common threat has ended. If the outcome is a stalemate, the PCs may need to enter negotiations toward peace.

Running at your table

How do you run mass combats? Do you need fiddly mechanics, or do you focus more on the broader story? How do you feel about the two Unearthed Arcana entries? Let us know in the comments.