• Heat is initially shared equally between players. Each player gets a 'copy' of every heat ember picked up; however, if one player dies and is (non-energy) revived by another, the second player will receive 30% of the first player's heat for reviving them. Having extra players does not decrease the amount of heat picked up per player.
• Crowns are equally shard between players. All players receive a 'copy' of each crown picked up. Having extra players does not decrease the amount of crowns received per player.
• Materials are apportioned randomly to the players by a Random Number Generater (RNG). It is theoretically possible for one player to get all the materials, but this is highly unlikely; it is far more probable that each player will receive a roughly equal percentage of materials dropped. The more players there are in a party, the less materials you are likely to receive.
• Equipment drops work the same way as material drops: they are also apportioned randomly by a RNG.
• Minerals are equally shared between players. All players receive a 'copy' of the minerals carried onto the elevator by a knight. Having extra players does not decrease the amount of minerals received per player; in fact, it increases it, since each knight can only carry one mineral chunk at a time.
• Heart drops occur in a separate instance for each person. The heart drop will time out if not used after 90 seconds. Using a heart drop will not cause another player's heart drop to disappear. It is therefore not possible to steal another player's hearts.
• Usable drops (pills, vials and Mecha Knight kits) are singular. They are the only kind of drop that go only to the person who picks them up.

Please note that going solo, leaving a party or being kicked from a party will cause you to lose all heat drops. Any crowns, materials, heat or equipment drops that are already exposed (i.e. not in treasure boxes) will disappear. This is in order to prevent cloning of desirable equipment drops.

tl;dr: Answer not in title, read the post >.>