Can you choose to not participate in combat?

Question

The combat rules state, on page 189 PHB:

Initiative determines the order of turns during combat. When combat starts, every participant makes a Dexterity check to determine their place in the initiative order.

Can a character opt to not participate in combat? That is, they do not roll initiative, they just huddle down and remain passive? So I can rule that they don't control any space in combat, in order to free up that space for the creatures that are acting in combat. (The noncombatants could obviously still be attacked, but would not have movement or actions like reactions, no Dodge actions, not be subject to the suddenly extended space requirements that active combatants need etc).

For example, the PCs escort a group of refugees down a narrow corridor and are ambushed by orcs. Can the refugees stay out of the fray and allow the PCs to move through or fight in the space they would otherwise take up (especially if everyone was walking much more closely than the wide spacing of combat)?

The question is not limited to NPCs.

Background

I think the underlying problem I have is that switching from narrative to combat mode changes the space requirements of a creature from how much space it physically needs to a suddenly much larger area, which in combination with the requirement that no two creatures may share a space, leads to various problematic outcomes. Like the one described above with the refugees, or like this one, where creatures would have to jump of a carpet of flying, just because someone attacks them, which is the question that caused me to ask this one - but there are many others conceivable. I am trying to understand if characters opting to not participate in combat could be one tool to address this rules artifact.

Answer 1

The DM controls the encounter

As the DM, it is your job to create the encounter and set the stage for the story you're telling with your players. If having NPCs not participate in the encounter makes sense for the encounter, then set the stage with them not participating.

I just ran an encounter where the PCs had to attempt a hostage rescue. I had the hostages on the map, but I didn't put them in the initiative tracker. They were still obstacles to move around and deal with on the map, but they didn't actively participate (other than being targets for the NPCs and provide another task, to rescue them, for the PCs).

Whether or not you have NPCs join initiative and combat itself is really just one of the tools you have in your storytelling toolbox.

Play the game

As for PCs, if a player doesn't want to participate, then that's kind of on them. Their absence will likely make the encounter much more deadly for their companions and they'll end up just sitting around the table while everyone else plays. To each their own? Or not, if you don't want someone not playing at the table.

However, if a player is asking to not participate in order to achieve a mechanical advantage or change how the game is played, then as a DM I'd be highly unlikely to allow that. That's playing a different type of game.

Answer 2

My answer would be no - NOT like you have described it. You want "not participating in combat" to mean:

That is, they do not roll initiative, they just huddle down and remain passive?

This is not "not participating in combat" - that is getting privilege.

To not participate in combat, a participant should:

• Roll for initiative as this determines order of action.
• Then, when it is their turn, move outward of the immediate combat zone and then huddle down there and remain passive.

That is within the rules. Unless their side is losing, a combat participant will have more to do than to deal with the dude trying not to get them outside of the combat. But their position is still relevant - i.e., someone may do an attack with area damage - as is initiative. Because unless they start outside of the group, they may even be in the front line and be attacked BEFORE they move.

Example:

For example, the PCs escort a group of refugees down a narrow corridor and are ambushed by orcs. Can the refugees stay out of the fray and allow the PCs to move through or fight in the space they would otherwise take up (especially if everyone was walking much more closely than the wide spacing of combat)?

Ah, but unless there is distance between the PCs at the front and the refugees, they still are attacked i.e., when the front gets hit by a little Molotov. Or from the side. They may also not cower but run to the back, hindering any PC from the back on the way to the front. It takes quite some mental strength to NOT run away when in fear - flight is a natural reaction. The ensuing chaos may as well neutralize part of the party. Unless there is no rear guard.