Are there rules on how PC can manage rank in a large scale battle?

Question

Does 5e large scale battle exist in spreadsheet form, or is it more ethereal like making strategic and creative decisions and inspiring the DM in roleplay?

Answer 1

There are no 'Official' rules published on managing mass combat for D&D 5E. However, Wizards of the Coast has published Unearthed Arcana (unofficial/playtest) material for handling mass combat

https://media.wizards.com/2017/dnd/downloads/2017_UAMassCombat_MCUA_v1.pdf

Bear in mind that this is playtest material and may not be well balanced. The ruleset is simulation-based where units of soldiers/creatures/etc. are abstracted as 'Units' of varying size and strength. You then run battle between these units.

I have not personally used these rules, and cannot speak to how well they work.