5e Mass Combat by Xillian

5e Mass Combat

Each Regiment size is calculated by HP value Add each mounts value to the rider's. No regiment may have more than 1k HP for the entire regiment. For foot regiments, round down to the nearest five. For mounted Regiments, round up to the nearest five. If the mounts can attack, include their HP in the calculation, otherwise divide their movespeed by 10, then subtrack the result from the base creature's Movement, adding the final sum to the original creature's HP value for this calculation.

Creatures which can cast spells have their HP value doubled for the purpose of Regiment size calculations. Different creatures can be mixed within a regiment, to a maximum of two (mounts notwithstanding), with PC's and Leader creatures being calculated into the Regiment size additionally before maximum units are decided.

Regiments make an attack roll for their relevant attacks (multiattack means multiple attack rolls still) for all creatures (including mounts if paid for). If the size of the creature permits (A creature may seat a number of smaller creatures equal to the size difference in Prime Numbers [ex: 3 goblins may ride a Giant Spider, while only 2 humans may.])

Attacks are made using the relevant ability score modifier to a d20. All abilities are to be factored in during combat. The defending unit must make a defense check, which requires the Armor Class to be used like an Ability Score with the relevant Ability Score Modifier applied to the defense roll. Defender always wins combat checks. On a successful hit, the damage inflicted removes that many units from a Regiment.

Once a regiment is at or below 1/3rd of its units, it must make a Charisma test (DC 10+ the number of enemy regiments within 1 hex) or it will become terrified and “Rout”. Regiments which are Routing are terrified until there are no enemy units within 2 hexes. A Regiment makes its Rout check off of the highest intelligence creature within its ranks, or one designated as a Leader (if the leader has not been killed). Regiments which are within 4 hexes of a Hero or Player Character may use their bonus if the individual is designated as a leader.

Regiments outfitted with reach weapons may ignore the benefits of an enemy which is charging. Units that engage and initiate the attack are considered charging. Charging units reroll 1's and gain a +2 on both attacks and damages. This bonus is doubled (reroll 1's and 2's, and +4) for mounted units that are not carrying their maximum number of riders.

Regiments may move one hex for every 10 feet they can move, and each turn is 20 seconds. If initiative is in use, units move on initiative. If it is not, all units move on a single turn (decided by opposed leader initiative checks each round) before combat is resolved immediately. If this option is used, a unit which moves adjacent to another enemy regiment must declare they are attacking the unit, or otherwise must keep 1 hex of space at all times from enemies.

When a PC is in a regiment, all attacks against them are applied to the Regiment first. Once they are the last remaining unit in a regiment, all damage is doubled before vulnerabilities are applied to account for scale, and attacks are applied to their HP. The PC may attack separately from their Regiment, or with it, adding their proficiency bonus to the Attack roll of the Regiment. Otherwise, the Regiment back up and support the PC.