I noticed after a particularly long run that some items I knew I picked up (like driftwood off a Lumber) weren't in my bag when I went back up to Haven. I died twice in the dungeon, so maybe you lose some items when you die?
Do you lose some materials upon death?
Powerups like health potions, throwing fire potions etc. go to whomever picks them up, crafting materials is split randomly amongst players, heat is all that is lost upon death unless you choose to revive yourself, then you lose both Heat and Energy.
if you die, you lose a percentage of heat that you have got, i think it's 10%. If you revive, you don't get these 10% back, and spend energy, but revive with full life. If someone revives you, THEY get the equivalent 10% you lost (so, theorically, summing all the heat that the party gets, you lose nothing), and they lose half their life, to revive you with as much health as they lost.
Because of that, caution with some people that enter your group, as i saw more than one time people that run the game getting all the health pills and better health bonuses, and that purposelly try to get the other party members in dyre situations where they will get killed, mainly to get their heat after this, so they can level their equips faster (at least in the closed beta).
everyones answers adds up to a whole :D loot is randomly distributed, no loot is ever dropped, consumables are never kept
If you're in a party, the materials and drops you run over might not be the items you take out of the dungeon. Party members take turns bagging items, and you can check the chat to see what has actually been added to your inventory.
Items that can be used in the dungeon do actually go to the person that picks them up.
As far as I know, you don't lose anything out of your inventory without choosing to use it or give it to someone else.