|Video game characters don't have stats.|
They don't breathe. They don't clean up.
Makes everything a very simple game.
It is the end of a battle and there are just a few creatures still fighting your party, while your character is past the point of effectiveness. Perhaps your low level mage is out of spells, or out of healing; you've thrown your last dagger or you're grimly hanging onto it. Your fighter is a hit point from death. You're out of this fight and you know it ... yet your friends are still at it, and a bad roll could kill one of them. You want to help. You just don't know what you can do.
I'd like to make a few suggestions. Some your character can do without preparation, and some things need to be set up in advance the next time you're in town.
For example, have a few flasks of distilled beverage or strong ale. If you're past worrying about the fight, it won't hurt to get a bit flushed ~ you're not going to need that attack die anyway, not now.
You can get some of the hirelings or followers to get out of the fight; they're just NPCs, and it won't hurt if they pull back and let the main characters mop up. Don't want some man-at-arms to catch a mace two rounds before the fight ends! They've done well; call them off the line, tell them to rest, tell them to drink from this flask and lift their morale; they've done their job and they can stop. Won't hurt to role-play a little and commend them, and help build their loyalty. After all, you're their boss.
As long as the fight's over, remember that there's a lot to be policed. Roll the dead into a pile. Gather up any weapons you can reach, or pick up the backpacks that were shucked off at a moment's notice and get them together in a pile, preferably near the door you're going to retreat through, or advance through. If necessary, assign a guard to watch it. Outdoors, get on it and gather some of those animals that have been left to the side, or jumped from in the fight. Those have got to be caught and brought back around.
Also outdoors, it wouldn't hurt to start clearing the ground to make a fire and a camp, if it's plain half the party will need to rest once the encounter is done. Gather some firewood. Find food. Get out your water flasks. Sometime in the near future I am hoping to install some dehydration rules ... so for gosh sakes, hydrate! Cool down a little. You're tired.
Underground, make some light; or find the lantern that's been set down, or the torch that's been in the hand of your lead fighter this whole time, and relieve the fighter of carrying it. You can always add illumination ~ everyone knows you're here now, so there's no need to play it coy. Get the room as brightly lit as you can, so when the search begins for secret doors, treasure, whatever, and when the bodies are being triaged, everyone can see clearly. Obviously, rifle anything that's dead ... but it doesn't hurt to get things ready for use, like make-shift stretchers, bandages, picks and tools, manacles if anything is still alive ... take a few minutes and get stuff ready.
You can always walk on ahead for a few dozen yards, checking out a tunnel or carefully examining for traps. Yes, that's a risk if you're low on hit points, but if you're drunk enough you might survive that trap. Surely, you're not going to run into much that hasn't already run away from the fight or into it. It doesn't hurt to carefully look around the next corner. Keep a mirror for that if it makes your mage feel better.
If nothing else, you can keep up the chatter. The party may be fighting zombies or something non-intelligent, but a little anthropomorphized insult can't hurt. "Come on, you beetle you. You think you're gonna take us down? Not in this lifetime!" If you can't actually hurt something, or risk being hurt, you can always taunt. Particularly the more intelligent creatures a few rounds before they actually go down. They might get mad enough that the DM has them lose their shit and get cut down in the process. Could happen. Depends on what you say.
There's really a lot to do. You could, you know, rest. Fighting is hard work.
I'd like to build into the system an overheating feature for combat, so that having to rest was a thing; where deliberately holding yourself back from combat, when you weren't needed, was a good strategy for when the front line has to fall back and rest.
But we need rules for that, and as I am often told, rules are a bad thing. Rules don't make anything fun.
Somehow, being able to fight or role-play incessantly, without limitations, without drawbacks, without consequences, without an evaluation of success vs. failure, sounds unbelievably boring, and anything but fun.
The player thought I was kidding. I am not kidding.