Using Errant Warbands in OD&D

 I've been wanting to have a way to streamline some of the combat in my OD&D campaign, namely reduce the number of rolls involved in the close quarters combat phase, where you have say 2 PCs and 3 mercenaries facing off against a group of 6 enemies and then just a whole bunch of dice rolls need to be made. 

My first thought was to try and adapt the concept of Warbands from Ava Islam's Errant. What you see below is where I got that to. I have run one playtest of this system during my game, which you can read a bit more about in this session report. 

The long and short of it is that I am not super happy with how this worked and it brought on a lot of questions regarding practicalities of it's use. 

However, just because something failed to meet it's goals, doesn't mean I shouldn't just share it anyway, so here we go. Maybe some of you can make better use of this. Keep in mind that this is written specifically for my own campaign's house rules, but I am sure you can easily just adapt elements to your own OD&D game without too many issues.

Warbands Rules

Mercs do not fight individually in combat, but instead augment the combat prowess of their leader (usually a PC).

Warbands come in Small, Medium and Large sizes, depending on the number of people in them, not counting the leader.

Small Warbands are from 1 to 5 people.

Medium Warbands are from 6 to 10 people.

Large Warbands are from 11 to 20 people.

Warbands have HP based on how many people are in it (again, not counting the leader)..A warband’s HP is based on the hit dice of its members, with every 1 HD member adding 2 HP, 2-3 HD adding 3 HP and 4+HD adding 4 HP to the warband total. For ease of keeping track of casualties, warbands are always composed of members with the same Hit Dice, maybe having 1 singular member who acts as leader (in which case they are not counted and instead have their own individual HP pool).

Damage is always dealt first to the Warband before it is dealt to the Leader. As a Warband loses HP it might fall from one category to another.

Attacks by individuals against a Warband are impaired, unless that individual has a means of hitting everyone in an area (a Fighter or Monster’s sweeping attack, a Mage’s AOE spell, etc). From there each step in size difference (individual, small warband, medium warband, large warband) incurs either an impairment (when a smaller group attacks a bigger one) or an enhancement (when a bigger group attacks a smaller one).

1 Level of Enhancement/Impairment gives +/-2 to attack rolls and +/-1 to damage rolls.

2 Levels of Enhancement/Impairment give +/-4 to attack rolls and +/-2 to damage rolls.

3 Levels of Enhancement/Impairment give +/-8 to attack rolls and +/-3 to damage rolls.

Here's how that looks, laid out in a table.

Additional Notes

Fighters that have a sweep attack add the bonuses/penalties to each attack roll they make. When using a sweep attack against a warband Fighters ignore the impairment from attacking a larger group, if they can hit all members of it.

A Sorcerer casting Maleficence on a Warband still does 2d6 hits to it!

For every 2 (or 3 or 4 depending on armor) HP that the warband loses, a mercenary is killed.

A warband’s AC is based on the AC of the Leader.

[I would have included some example combats here, but blogger is insisting on completely fucking up their formatting so I just gave up after the third try.]