The description of the Rod of Rulership says:
You can use an action to present the rod and command obedience from each creature of your choice that you can see within 120 feet of you. Each target must succeed on a DC 15 Wisdom saving throw or be charmed by you for 8 hours. While charmed in this way, the creature regards you as its trusted leader. If harmed by you or your companions, or commanded to do something contrary to its nature, a target ceases to be charmed in this way.
The description of the Charmed condition states:
- A charmed creature can’t attack the charmer or target the charmer with harmful abilities or magical effects.
- The charmer has advantage on any ability check to interact socially with the creature.
Per the "Military Might" section in the description of hobgoblins in the MM, hobgoblins are used to following the chain of command:
In their martial society, every hobgoblin has a rank, from the powerful leaders and champions, to the rank-and-file foot soldiers (…)
Assume the player characters have successfully charmed a tribe of Hobgoblins by presenting and activating the Rod, but the hobgoblins' leader succeeds on the save and is not charmed.
What happens if the characters demand obedience from these Hobgoblins (e.g. commanding the hobgoblins to follow them), but their leader objects?
Best Answer
It's up to the DM.
Ultimately, the DM controls the NPCs, but we can give an examination of the factors at play here to provide some guidance for how a DM might rule on this situation. Consider the effect of the Rod of Rulership:
So you now have a group of hobgoblins that regard you as their trusted leader. However, the rod does not say that you supplant any trusted leaders they already have. To me, it seems like now the hobgoblins have two trusted leaders, and how they respond to the conflicting commands from those leaders is up to the DM.