D&D 5E My homemade 5th Edition Mass Combat Rules (Based on Handling Mobs)

[Nickolaidas]

This is a system I just came up with, and I want to hear your thoughts.

Basically, I take the rules of "Handling Mobs" in DM Guide page 250, and expand on them a little.

My design is the following:

An army has a total of hit points based on Monster HP x Number of soldiers.

The army has five stages of effectiveness, based on the amount of hit points. The effectiveness is a multiplier which affects damage per round.

100% effective = full hit points
75% effective = total hit points down to 3/4
50% effective = total number of hit points down to 2/4
25% effective = total number of hit points down to 1/4
0% effective = army destroyed
NOTE: A change in effectiveness takes place in THE BEGINNING OF THE NEXT ROUND!!

Each round the army chooses how to attack, based on a regular / unique attack it has.
Damage is multiplied based on how many soldiers hit.

Repeat each round until an army is routed or destroyed.
Note: An 'army' which is composed of a single unit, i.e. the Tarrasque, has no penalties for lesser effectiveness, and always hits once, regardless of enemy AC.

EXAMPLE BATTLE

An army of 50 guards attacks an archfiend to protect their city from demonic invasion. Initiative is rolled, and the guard army goes first. The guards have 16 hit points each, giving them a total of 800 hit points. The Archfiend is a single monster with 400 hit points.

ROUND 1:
The guards need a 20 to hit the archfiend (because it has an AC of 23). Based on the Handling Mobs rules, this means that 1 out of 20 guards hits the monster this round. Since the guards are 100, this means that the multiplier for damage is x5, and the effectiveness is 100%, which means no penalty. The guards roll 1d8 and get a 6. Multiplied by 5, the guards gave the Archfiend a total of 30 hit points of damage. Of course, considering the fact the monster is immune to normal weapons, the damage is in turn, turned to zero.

On its turn, the Archfiend chooses to use a Mass Fireball spell instead of attacking once in melee. Rolling the dice, the spell causes 200 hit points of damage (theoretically - I'm not even sure if the spell can cause so much damage). The guards roll a saving throw (once, affecting all), and fail, taking 200 hit points of damage, bringing their total hp to a 600. This brings their effectiveness down to 75%.

ROUND 2:
The guards keep doing their thing and roll 1d8 for damage against the Archfiend. They roll a 4, which multiplied by 5 makes it a 20. However, their effectiveness is down to 75%, which means they get a multiplier of 0.75, bringing their damage to a total of 15 hp this round. Again, all that damage is negated because the damn thing is immune to mere weapons.

The Archfiend makes another Mass Fireball spell and the guards fail their saving throw, taking another 150 damage, bringing their hp total to 450 (still at 75% effectiveness). Or it could use a single melee / ranged attack, or do something else ...
-----------------------------------------------------
EXAMPLE 2 - ARMY VS ARMY

2000 human soldiers vs 1500 orcs

ROUND 1:
2000 guards (each having 18 hp) give us a total of 36.000 hp (THAT'S A LUTTA NUTS!!) AC 16
1500 orcs (each having 22 hp) give us a total of 33.000 hp. AC 13

ROUND 1 - Guards won initiative
The guards need a 10 to hit an orc - based on the Handling Mobs rules, half of them hit. They roll a 1d6+1 and get a 4. Multiplied by 1.000, this means they caused 4.000 hp of damage to the orcs.

The orcs need an 11 to hit the guards, so they get the same treatment and get half of their units to cause damage. They roll a 1d12+3 and get a freaking 15 - multiplied by 750, to a total of 11.250 hp this round.

ROUND 2
The guards are fewer than 27000 (their 3/4 hp total) which means they're now at 75% effectiveness. Their damage will now get a 0.75% multiplier. They roll for damage, get a mere 2, multiplied by a thousand, and then by 0.75 for a total of 1500 hp.

The orcs have a current hp total of 27500, which isn't enough to take them to 3/4 of their hp total, which means they're still fighting at 100% effectiveness. They roll for damage and get a 10, multiplied by a thousand to bring a devastating blow of 10.000 hp to the guards.

ROUND 3
The guards have seen much better days ... with their current hp total at 14.750 - less than half hp total, they're now at 50% effectiveness. They get a multiplier of 0.5 each time they do damage.
The guards roll for damage and get a 6, multiplied by a 1000 and then a 0.5, to total of 3.000 hp.

The orcs (still at 100% until the next round), attack and get an 8. Apparently, Gruumsh favors his sons this day, to a total of 8000 hp of destruction.

ROUND 4
The guards are a shadow of their former fighting strength, with a mere 6750 hp pool, less than 1/4 of their total hp - they're now down to 25% effectiveness, giving them a penalty modifier of 0.25. They make a desperate attack at the orchish horde and roll a 4, causing them a total of 4x1000x0.25 damage, which translates to 1000 hp. In short, they're screwed.

The orcish horde has FINALLY began to weaken, with a hp current total of 24500, which is (by an inch) less than 3/4 of their hp total. They're down to 75% of effectiveness. They roll for damage and get a terrifying 11, multiplied by a 1000 and then by 0.75, to a total of 8250 hp. This surpasses the current max amount the human guards had - the human army is completely butchered, down to the last man.

Remaining orcs: The orcs began at 33000 hp and finished at 23500, which means that out of 1500 orcs, only 1068 remained (divine the remaining hp total with the hp an individual orc had). The horde feasts on meat and wine as they celebrate their victory during the night and honor their fallen comrades.
----------------------------------------------------------------------------------------------------------------------
So, what do you guys think? Does this system work?

 

[Ancalagon]

Hello

1: clean up the math a bit - is there 100 or 50 guards in your first example? And you have to figure out how area of attacks work vs an army.

2: When two army face each other, not everyone in the army gets to attack. There are guys in the back essentially - only the front line gets to participate.

3: Why do you assume "average" to hit rolls but not average damage rolls? I agree that randomness is good, but it seems a bit arbitrary.

4: How long are these rounds? A battle between 2 large army is over in less than 30 seconds? This is related to problem #2.

I would recommend you look at post #7 on this thread http://www.enworld.org/forum/showth...ning-Larger-Battles-Efficiently#ixzz43z2QJaRu exploder wizard had an excellent quick system.

 

[Nickolaidas]

Thanks for taking the time to comment on this. This is a very rough draft I'm thinking about, so the armor has more than a few chinks.

#1: Yup, that's a typo on my part.

#2: For simplicity sake.

#3: Because that's how Handling Mobs worked in 'to-hit' situations. Based on the enemy's AC and the attacker's +x value, the number of successful attacks is automatically calculated. But I want damage to have randomness, otherwise an army who has an hp advantage is almost sure to win.

#4: I know it isn't realistic, but realism isn't really what I'm going for here. Still, you've got a point. Thanks for the feedback.

 

[DM Howard]

This is interesting and I will have to give a try in my upcoming Mystara campaign. Usually I have opted to use an extended skill challenge to adjudicate large battles and sieges.

 

[Xeviat]

I'm going to look at this more thoroughly when I get home. 3E and 3.5E stuff works well in 5E with minimal changes, so this should work well. It's a thing I'd like to use in my games too.

 

[nomotog]

I thought the mob rules worked differently then what you have here? I thought they worked more as monsters with some different flavor?

I would totally change your attacking formula. It's kind of complex and it works totally different then other attacks. My idea is that an army gets to make an attack vs everyone next to it. On a hit they deal full damage, on a miss they deal half. Attacks would be considered area attacks, so evasion comes into play and armies take double damage form arena attacks. (Some armies could get arrow volley attacks that are a simple aoe attack like a fireball, and you could make up all kinds of attacks to represent different military moves like a charge, or a encircling.)

You don't want 4 different levels of damage. I say just do one at half HP that drops their damage output and maybe includes other effects based on the kind of army. A orc army might actually get more deadly when they are at half HP for example.

 

[Finneris]

Excellent system! I would only use it to figure out battles where the PCs don't play a huge role. This type of system doesn't give the players a lot of agency but, if they are low level soldiers or not in the battle at all then, that's not necessary. I can see this being used to determine how the whole army reacts as opposed to just the PC's actions. It seems easy enough to make some additions to it to make different tactics to allow more dynamic play. How would you edit the system if a PC was leading the army?

 

[Nickolaidas]

I will probably update the rules tomorrow and give it a more concrete feel - although most of the things that annoyed you guys are still there. As for the math, I don't think it's really hard if the army owner has an army sheet which has the amount of hp at 100, 75, 50 and 25 percent accordingly. And with a calculator in hand the army attack is resolved quite fast (though I admit, by mere human memory it can be daunting and unfriendly). I really don't want to throw away the dice roll or the effectiveness values (the dice adds tension to the attack and the Effectiveness rule is a good tool to make you want to preserve a particular friendly army unit or egg you to quickly take out an enemy one).

Again, thanks for all the cents!

 

[Nickolaidas]

How would you edit the system if a PC was leading the army?

I will write about this tomorrow - basically the PCs and the monster commanders are called VIPs, they possess the ability to find and take out particularly troublesome units or be a tool to roleplay a particular type of encounter (i.e. have the PCs go and sabotage the ballista of the hobgoblin army in order to take it out from the rest of the fight).

Taking out the Enemy Commander forces the army to roll a d12. On a 1-6, the army retreats with lost morale. On a 7-12, the army stays and fights, but the Hit Probability Table for all attacks goes one (maybe even two) step(s) down as a permanent penalty for the rest of the fight. For example, the orcish horde above can hit the human guards as in the '1 out of 2' category. With their commander killed, they would automatically fall to '1 out of 3' (or '1 out of 4') category. This imposes a respectable penalty to the enemy army which makes the death of the commander a legitimate strategic move.

 

[nomotog]

I will write about this tomorrow - basically the PCs and the monster commanders are called VIPs, they possess the ability to find and take out particularly troublesome units or be a tool to roleplay a particular type of encounter (i.e. have the PCs go and sabotage the ballista of the hobgoblin army in order to take it out from the rest of the fight).

Taking out the Enemy Commander forces the army to roll a d12. On a 1-6, the army retreats with lost morale. On a 7-12, the army stays and fights, but the Hit Probability Table for all attacks goes one (maybe even two) step(s) down as a permanent penalty for the rest of the fight. For example, the orcish horde above can hit the human guards as in the '1 out of 2' category. With their commander killed, they would automatically fall to '1 out of 3' (or '1 out of 4') category. This imposes a respectable penalty to the enemy army which makes the death of the commander a legitimate strategic move.

If you stat out the armies a monsters which is what I think you are doing. (It's how the mob rules worked) Then you can easily just have the players engage directly with armies. They can buff them, heal them, attack them, charm them, ect. (Unless you directly stop some actions, but I think you can leave most in with only minor logic bending required.) Also you can just give players their own units to command. Also use smaller groups of people. Like in example two brake up the orks into 6 armies of 250. (Having more then one amy lets you do more tactically too.)