My party recently had a very dangerous encounter. We expended close to 100% of our resources in one combat, killing all but one enemy, while losing two of our five members. The last enemy was healing itself (while killing us) faster than we could deal damage to it, so we ran. Now our GM is saying we've lost that experience we would have gained for all our successful kills in the combat because "we were defeated" and had to run. Maybe it's just me, but I feel we deserve the XP for the monsters that we defeated.
By his logic, say a wizard destroys a small army of orcs using all of his spells, only leaving one survivor, but fearing the last enemy will win in a fist fight, the wizard retreats and no longer gets XP for the 100 other orcs he fireballed and such.
Or say your party is fighting a bunch of monsters, and just before you kill the last one, a second wave of monsters arrives. Your party flees this second wave, but since initiative was never dropped, you lose all the XP from the first part of the encounter.
If that's RAW or RAI then fine, whatever, but I feel like realistically the characters would learn and grow from the combat. We risked our characters lives (and lost 40% of the party) to kill off the creatures that we did, and now we're being told it was for nothing. We get no XP for the kills now, but the monsters are now dead and gone, so it would've been better for us to have run without killing them so we could kill them later?
I would even be okay with a ruling of we get XP for them all once we return and defeat the last monster, but that's not what our GM is saying either.