How To Do a Mob

[GreenTengu]

I don't have any good mechanics for this right now myself, I was wondering if anyone had some ideas on how to do it. What I want to do is come up a with a pretty clean way of doing a mob of enemies.

The idea would be a situation where you would have a large number of enemies, at least 10 and outnumbering players 2:1. Whether it be demons pouring out of a portal or an enemy army charging or guards rushing into the town square to engage with the PCs.

In any of these scenarios, the number of enemies means you generally don't want to have to bother to track the exact position, health, or specific action of any of the enemies. Instead this would be more or less left up to the imagination of the players. There are just too many of them and they are individually so far below the power level of the players that the heroes can defeat them individually quite easily.

The other things to focus on would be that one should not need to make more than a single attack against each player representing the enemies that focus on them, and the fact that in many of these scenarios the enemies engaging with the heroes is very likely to grow in size and become better coordinated as the battle wages on. So in a scenario where the heroes need to hold back an army of 50 skeletons for two minute while the spell to dismiss them is being prepared or they need to hold off the enemies pouring out of the fortress while their escape route is being prepared-- the players don't get hit with 50 attacks on the first turn, but the numbers are likely to grow faster than they can cut them down and it is going to become harder to avoid damage and the amount of damage possible can increase. So basically this would be ideally leveraged in situations where the heroes are very likely not to win in the long term if they decide to stick it out until the end, but they would have things easily in hand for the first few rounds.

Ideally I think I want to treat this as a single enemy starting with high hit points but very low accuracy and attack power that basically regenerates, and as its hit points rise so does its accuracy and attack power, but if the heroes manage to lower its hit points quite a bit both its accuracy and attack power decrease. It should be able to affect all targets "in melee" with more powerful attacks and those at ranged with less effectiveness since less of the mob are likely to be equipped with ranged weapons.

The major issue I can see arising is how magic, particularly single-target and multi-target blasty magic works in the game. Conceptually I would think that they would, beyond the initial round, be as scattered as the party and sort of mixed in with them or something. Or just randomize how many "targets" the area blast hits depending on how large of an area it generally affects and then multiply the damage by that amount.

Has anyone worked on anything of this sort?

 

[Celebrim]

Mob's - like any large group - are extremely difficult to handle. Attempts to handle this as single creatures usually break because they overestimate the power of a mob. Attempts to handle them as a mass tends to result in crushingly slow and repetitive gameplay.

If you are going to handle a mob as a single creature, take particular care to work out your math to make the results correspond to roughly what the finer resolution game state implies. One important thing to note is that how dangerous a mob is depends on the number of squares adjacent to you occupied by the mob. This is why formations are so effective against mobs. Resolve the mob as a single relatively weak attack that gains a +1 bonus for each square beyond the first adjacent to the attacker occupied by the 'mob' plus any flanking bonus involved. This represents that most members of the mob are basically taking an 'assist other' action. I find that giving the attack exploding dice for damage as a special effect or giving the mob a bonus attack if the target is flanked by the mob works better for the sort of damage curve you'd expect for a mob attack than giving the mob a big single attack. In 5e, you might give the mob advantage on damage inflicted. But it's perfectly fine to resolve the entire mob as a single attack on each adjacent target doing 1d3 or 1d4 damage.

The biggest danger of a mob is their ability to use their mass to trample down something. A mob that hits should get an additional trip (to knock the target down) or bulrush attack (to move the target where it can be more easily surrounded). Also, a mob should get either improved critical threat range or a bonus attack against a prone target, representing the danger of trampling. I prefer the critical threat range to bonus attacks because you end up with less die rolling, but which is better will depend on the rules set you have and what it allows.

Instead of hit points, track the mob by the number of squares it occupies, where each attack doing 3 or more damage (for example) eliminates a square. Area of effect attacks eliminate a number of squares according to the area that it effects.

Using these simplifications, you get a reasonable compromise between treating it as a single attacker (with implied massive hit dice, see the Swarm template for where this can go wrong) and treating it as individuals that each have actions to track.

An alternative approach is to use a mass combat system of some sort, but I've never seen one of these I can really recommend.

 

[transcendantviewer]

How many individuals are in the mob? Take that number, equate it to a die roll. The result on that die roll is how many attacks the mob makes on its turn. Aside from that, just alter the number of hit dice to reflect how many people there are. For example, there's a mob of 20 people. At start of the mob's turn, roll a d20. That result is how many attacks it can make in that turn. Then roll an attack roll for a few of them and apply it to some more, group checks and whatnot. Aside from that, don't let the mob get more than 8 attacks off against a single medium sized creature in any given turn. Its space should be reasonable for its size. I'd say a mob of 20 would fill a huge-sized space. And, of course, we'll use Commoner stats. The mob of Commoners would have 20d4 hit dice. Well, that's the fast and easy way I'd do it.

 

[molotdet]

I created one adventure that had a random mob encounter. it was created for AD&D (though partially converted to 3.x) and made to represent a human mob but you should be able to extrapolate what you need from this base. Also the mob was not actually attacking the PCs in this case, so if that is your intent you might want to edit this a bit so you can represent that the PCs are the targets of the mob.

To put this on a grid, fill every hex/square around the PCs with mob characters and continue out in a square. to represent a shift in the crowd move the outside 2 lines of models to the opposite side . to represent PC movement simply move the mob model inhabiting that space into the space the PC inhabited (a moving PC increases the chance it is knocked down by +2). When/if the PCs kill a mob member, instead of removing that model, remove one from the outer edge of the mob (to represent a tide of people pushing through the mob).


Mob or Looters (3d20 x 10 persons): Each specific member of the mob has the following statistics…

0-level human (or appropriate being)
HP: 3
AC: 10
MV: 30
To-Hit bonus: +1
#AT 1; Damage by weapon type; Knife, club or torch;
Morale 8

This is a fight between rival gangs or a general riot. PCs will be engulfed by the mob and will each be attacked by a random participant each round. PCs are always considered flanked for purposes of attacks. No attacks of opportunity may be made due to the ensuing chaos.

Land Movement inside the riot is limited to 10 feet per round regardless of a PCs speed. PCs can work their way through the riot in any given direction as they choose. The outskirts of the riot shift 10 feet in a random direction every round. The riot lasts for 6-60 (6d10) rounds.

For each turn that the PCs are engulfed by the mob, roll 1d20 to check for each of the following incidents for each PC. It is possible for each PC to suffer all the following in every turn. These are random events and therefore bypass any defenses a PC may have against such attacks:

1) Inventory Loss: On a result of 1: PC loses a random object from its equipment list in the crowd (accident or pick-pocketed); the object should be valuable but the object should not be something that will hinder completion of the adventure.

2) Knock Down: On a result of 1 or 2; PC is knocked down and trampled by the crowd (2d4 damage).

3) Random Projectile: on a result of 1 or 20; the PC is hit by a random projectile (bottle, board, or rock) that was not necessarily aimed at them (d4 damage).

 

[Eltab]

Another way to handle a mob would be to treat them as a Swarm (of medium-sized creatures, in this case) that fills multiple squares. Keep a note to yourself that Commoners have 4 HP and you get an idea how many people the heroes are taking down with their attacks.

A mob that "heals HP" can be described as more people coming and joining in. You may want to place a special person - somebody who is inciting bystanders to join in the fight - who can be incapacitated (by Silence spell or by an arrowshot or maybe a boot thrown at his/her head). After that the mob is unable to replace its losses or recruit more strength.

 

[Bupp]

I've used a tweaked version of the swarm for a fight against a tribe of bullywugs. For stats I kept it simple. For every 10 bullywugs, I used the stats of a hill giant. Hit points were pretty close, and instead of making 10 separate attacks, I made the two hill giant "great club" attacks, and let them represent a myriad of hits. That way each "attack" represented about 5 bullywug attacks.

The math seemed fairly close, and the the players never realized I was just using a big pool of hit points. Much easier rolling two attacks than ten!