Hello, I would appreciate some alternative idea's on how you when DM'ing assign experience to a party when they are victorious in a battle but had allied friendlies. I know some locally that just assign full experience to the party, and some that give a share, diluting the total to other fight contributors. (even if it has no effect as they are NPC)

I have so far been assessing this in the following seperate categories,  please share your opinions. 

Permanent* familiars and mounts - no share

Allied spell summoned creatures that cost a spell slot resource for the fight / day (most conjures and all animated and created undead) - no share.

Semi/permanent long term summoned / charmed minions (planar binding / thrall of the awakened / mass suggestion victims - full share.

Magical minions summoned from non party spell sources (bag of tricks / elemental gem / brazier / long term planar binding's - full share.

Assistants that are under no compulsion but assist anyway (or are allied) - full share

These are the guidelines I currently use, they developed from attempting to balance the use of hordes of controlled creatures versus those that have to maintain their spells on a short term basis.

Please discuss.

I would definitely not penalize for allies gained by charming with a spell or class feature or gained by using an item as these still took resources from the party.

As for allies gained by circumstance or role play, I would only penalize exp if the ally is of comparable strength to the players (i.e. with a CR at half the players' levels). Depending on situation, I would award bonus exp for defending weaker npcs.

Familiars, Mounts, Summoned stuff and whatever don't get exp anyway so it doesn't matter.

If a character does something via familiar, bag of tricks, summon spell, it's from that character so they should get exp even if the character herself didn't do anything but pull tricks out of a bag.

I generally just give the whole party the same amount that I think they should get and maybe a bonus for creative role play or extra clever ideas. Usually the joy players get from their clever idea succeeding in the first place is enough of a reward. Giving exp for neat plans sometimes results in players trying dumb things just to get a bonus.

I calculate the xp based on the number of PCs alone. Whenever they use items/spells other things that makes a fight easier, they're still using resources and making the right choices in order to do so. Same goes for environmental effects; if a player thinks of something cool in the environment to make the fight easier (like picking up a torch from the wall to fight a swarm of bats when they only have a sword) that's fine by me. I want to reward that kind of thinking. For instance; I've now given my players an item that can be used once to summon a guardian naga to aid them. That's a gamechanger in most combats; they'll either be able to handle something they normally could not or make something that's somewhat of a challenge into a cakewalk.

What I do, however, in order to keep things interesting is when I know they're going to have an ally for a fight I add that as a character to calculate my xp threshold for that encounter using the rules in the Xanathar's Guide to Everything. For example; the party consists of 4 characters that are lvl 5. This means that if I want to pit a couple of bugbears against them, I'd probably have around 10 since according to the table in XGtE 1 lvl 5 character is approximately the same as 2 CR 1 monsters. The other way around though, means that a single bugbear counts as a 4th level character. So that means that when a bugbear would join the party of four lvl 5 characters, they would now be a party of five characters, one lvl 4 and and four lvl 5. This balances the xp gain and difficulty out easily. The same can work for mounts or other "allies".

Anytime a creature or any other effect on the difficulty of a combat costs some form of resources, either from a magic item or spell or otherwise, I don't recalculate xp. I mean, sure; conjuring two crag cats using a conjure animals spell significantly changes the flow of combat. Then again, using that same 3rd level spell for a fireball could have the same or even greater effect.

Thanks for the input, no surprises so far! Where would you rule when a druid has X+ Awakened trees with him, its a spell  but not using the days resources?

Quote from Moondruidsneversleep >>

Thanks for the input, no surprises so far! Where would you rule when a druid has X+ Awakened trees with him, its a spell  but not using the days resources?

 I would add them to the party as a cr 2 creature/lvl 5 character, then calculate xp accordingly. Again, I'd prefer to up the challenge rather than divide the xp so the players don't really feel punished for having allies/using their abilities. IF they awaken the trees during the encounter and perhaps "release" them afterward I would not count them.