minecraft-java-edition
So lets say I'm making a map in Minecraft. No mods, no bukkit, no anything; just command blocks. and I have this one mob that I don't want players to be able to kill.
Normally, I would simply give it a resistance potion so that it couldn't be hurt, but I want other mobs to be able to hurt it, just not players.
Is it possible to make this mob unkillable by players, but still able to die by other mobs?
This was a very interesting challenge for me to work out. There are many parts to this problem, which are a lot harder to accomplish than one might think. There's identifying the player with the status effect, and identifying a set of random players who are not them (since /tp Unionhawk Unionhawk is a valid result of /tp @p @r, and does nothing).
But, finally, here is my setup, which works for a bounded number of players on a server. Some of its flaws include only allowing one game to be played on a given server, and using experience level to identify players. As such, /gamerule doMobLoot false must be used, and /gamerule commandBlockOutput false is strongly advised.
So there's quite a lot of things going on here, as you can see. But this is all accomplished using 4 commands and a hopper clock.
The Group 1 command blocks are there to detect when a player has the specified potion effect, remove it, and proceed to the matching Group 2 command block. I used /effect @p[c=n] 4 0 for that one, which removes the mining fatigue effect from player n on the server (going down the list of players on the server). When that command evaluates, the Group 2 command blocks give that player one level of experience using /xp 1L @p[c=n].
From there, the next time the hopper clock pulses, the "Group" 3 (you only need one) command block teleports a player with 1 level or more to a random player without any levels using /tp @p[lm=1] @r[l=0]. When this command evaluates, the "Group" 4 command block clears the experience level of all players using /xp -9999L @a.
I am experiencing the same issue. I am using single rows of cursed earth, so that might be the issue here. If you are using the same method, that might be the reason our farms are not working. A screenshot of your farm design would help.
Edit: Alright scratch that. I just found the reason for my problem. I am using Mo'Creatures (which requires Custom Mob Spawner). CMS is not playing along nicely with the code of Cursed Earth and that is the reason for mobs not spawning on it.
Best Answer
/summon ExampleMob ~ ~ ~ {Invulnerable:1}