D&D General Large Scale Battles - How do you DM them?

[Werehamster]

In my world, it's been 250 years the last big war between the Orc armies and the humanoid nation they attacked. There is rumbling that the Orc armies are re-gaining confidence and small skirmishes have been breaking out on the borderlands between the two territories. There is a definite possibility that there will be large-scale battles with armies involved.

I've been trying to wrap my head around how to run a game where the party is involved on the battlefield with hundreds of Orcs and Humanoids are running around all over the place and how to determine the ebb and flow of the battle. How many soldiers/orcs die each round? How to decide if the party is directly targeted? When is morale for each army decided to see if they retreat/surrender?

Have any of you done this type of scenario, and if so, how did you run it? Also, what worked and what would you do differently if you did it again?

Thanks in advance!

 

[overgeeked]

Focus on the PCs and what they’re doing in the battle. Either they’re a squad with support troops or they’re each leading a squad with support troops. Some players just are not into wargames in their D&D. Others are.

The battle around the PCs can be handled anywhere from pure narration to a die roll to full systems of their own. Check out Matt Colville’s video titled Warfare. He’s got a great short series on politics. He’s also got two books on warfare for 5E. Strongholds & Followers along with Kingdoms & Warfare.

 

[Lyxen]

I have always used the BECMI War Machine throughout all the editions, it's simple, it can be resolved using Theater of the Mind, and it works for battles with scores of combattants to armies of millions. Here is a bit more read about it.

I have a 5e conversion, but I can't post it here since it still has parts of BECMI in it. I can however share a few tools.

 

[Oofta]

I've always just had the PCs be a special unit. Sometimes they're charged with gathering intel on the enemy, taking out an enemy siege machine or defending a defensive weak point. They're the equivalent of special ops forces, not grunts on the front line, although that may not be how they start.

You certainly can find rules on how to run armies, but just because someone is an ace fighter it doesn't necessarily follow that they are promoted to generals of armies.

 

[ninjayeti]

The easiest way to run a battle is to treat it as normal combat for the PCs with the rest of the battle being done narratively. I usually set the "default" result of a battle, and give the PCs a specific objective based on the overall narrative. If the PCs succeed in their objective they shift the result of the battle slightly in their side's favor.

For example if the default result for a battle is the PCs side getting overrun, the PCs will need to hold off several waves of enemies for X rounds to cover the retreat. If the PC's succeed, the outcome changes from a rout to an orderly retreat. Similarly, if the default for a battle is a stalemate, the PCs are tasked with breaking through the enemy's line - they have to wipe out a defending force which is getting reinforced every few rounds as the enemies try to shore up the weak spot. If the PCs succeed, the result of the battle changes from a draw to a narrow victory.

Another easy way to run battles is to group NPCs in to units of the same size (usually 5 or 10 individuals in a unit). For example, you can run a fight between 20 knights and 100 goblins as fight between 2 knight units and 10 goblin units. If the PCs get involved you can "unpack" some of the units to run them normally. So you could run the above fight as 2 knight units against 8 goblin units plus the PCs against the remaining 20 goblins.

 

[Hexmage-EN]

I like playing around with this site's combat simulation tools for battles between NPCs:

D&D

The decisions the computer makes for the characters don't always make sense, and some monsters seemingly don't work correctly (such as beholder zombies), but it's good for a rough estimate to see if, for example, a single death knight could defeat a horde of fifty skeletons and zombies (the answer is yes; destructive wave alone takes out more than half of them).

EDIT: Apparently ten veterans (CR 3) can reliably kill a horde of 50 goblins (CR 1/2) within 5 rounds of combat: Simulation

 

[Greggy C]

The decisions the computer makes for the characters don't always make sense, and some monsters seemingly don't work correctly (such as beholder zombies), but it's good for a rough estimate to see if, for example, a single death knight could defeat a horde of fifty skeletons and zombies (the answer is yes; destructive wave alone takes out more than half of them).

One day I will stop breaking stuff accidentally.

 

[Hexmage-EN]

Oh, you're the one who made it! Thanks so much! I play around with it a lot.

 

[Jacob Lewis]

This book still works well with any edition.

 

[Ralif Redhammer]

My approach is, as others have said, to focus on the PCs. I kinda treat it like a big bloody sandbox. For example, I'll tell them that they see heavy infantry coming towards them, a wizard over there blasting their side with fireballs, and an injured captain on their side in need of rescuing. They can decide where they go from there.

There will also be events that occur suddenly during the battle: Enemy cavalry preparing a flanking maneuver, a maddened behir on their side goes on a rampage, archers strafe them, etc. Battles are dynamic and unexpected stuff can come up.

The outcome of the battle will be determined by their success at these encounters. I also assign certain options as expiring in X number of event choices. The captain is going to die if they don't get them within two encounters, and will badly affect the morale of their side. If they fail to do that and avoid rather than stop the archers, then the battle could be lost.

One thing I've learned the hard way is that if you want to put the PCs in command instead. rather than in the proverbial trenches, there's likely going to be someone that wants to just fight on the frontlines, and that's going to be a headache to meld the two. The party needs to decide as a group which approach they're taking and not try to do both.