What are Companion NPCs?
This campaign will have NPCs that serve a much more active role in the game and once they have bonded with a player character, they can become a semi-playable character! Any NPC can become a companion. Their character sheets are very simple and they don't have skills, they just grant advantage on certain skill checks. Companions have no traditional levels, but can become stronger after some time has passed.

To keep NPC companions simple, they typically possess a lower level abilities compared to PCs.
For example a "Bard Companion" will possess Bardic Inspiration, and a "Fighter Companion" will have "Second Wind".


Rules in Combat

Ally NPCs are semi-controllable by the players. On the Ally NPCs turn, the closest player (character) is asked what this NPC should do on their turn.
The player can discuss with the rest of the table, but what they do is their decision. If multiple players (characters) are nearby, they can choose together. 
They can choose from the following options:

Movement

  • Remain stationary

  • Move towards foes or an objective

  • Move away from foes or an objective

Actions / Bonus Actions:

  • Attack (use a weapon or an offensive ability)

  • Defend (take the dodge action or use a defensive ability) 

  • Support (provide a buff or help someone nearby)

  • Heal (heal an ally or themselves)

  • Custom instruction

Reactions

  • Custom instruction


The DM will then choose an action that matches their choice if there's no conflict of interest.

Conflict of Interest

Some NPC’s personality can clash with certain commands and they may refuse. When this happens, they will refuse to follow through on that command and choose another action or do nothing.

Affinity

When an NPC has bonded with a player character, the player is offered the choice to fully control that character during combat, or follow the existing Combat Companion rules.