To explain, when a player kills certain mobs, they have a chance to drop specific items. For example, when a player kills a zombie, they have a chance to drop iron tools, armour, iron ingots, and even potatoes or carrots.
If I wanted to create a mob-grinder, is there a way to spawn mobs that act as if they can be killed by players, if a player hasn't actually touched them using only commands/command blocks? (No mods)
I don't quite understand what you mean but there were 2 things I thought you could have meant.
The first one was to spawn the Mob with half a heart so there a one-shot-kill and for that, you would do: /summon Zombie ~ ~ ~ {Attributes:[{Name:generic.maxHealth,Base:0.5}]}
The second thing I got was to make the Mob Invulnerable and for that, you would do: /summon Zombie ~ ~ ~ {Invulnerable:1}
However, if you're trying to spawn a mob that has an attribute to define "Hit by player", unfortunately there is no such command.
/summon Zombie ~ ~20 ~ {Attributes[(hit by player)]}?
Mobs can drop items even if they die from other sources. The only thing they won't drop is XP. If you want to "farm" them put the command block to spawn them near a sure-death trap.
