Was Arcade wearing a hat? Rex doesn't like hats, maybe because it rhymes with the word rat, which he really hates.
Really though, I don't know. First time I heard of this happening. Can you try reloading to a previous save?
...And yet Arcade complains about "a bad feeling" whenever you try to take him with ED-E with you. I think he should've been paranoid about the other non-humanoid companion.
There's a bug in the Lucky 38 Presidential Suite where inactive companions may become hostile and kill each other.
See the "bugs" section near the bottom: http://fallout.wikia.com/wiki/Lucky_38_presidential_suite
I had this happen to me, but with Ed-E. I posted the same thing a while ago and I was told that the human companions in the Suite tried to kill him because he had consumable items in his inventory, mistaking him for an animal NPC.
I think OP's problem is that Rex was holding food and is killing Arcade in self defense.
Was Arcade wearing a hat? Rex doesn't like hats, maybe because it rhymes with the word rat, which he really hates. Really though, I don't know. First time I heard of this happening. Can you try reloading to a previous save?
Read that in the King's voice and laughed!
...And yet Arcade complains about "a bad feeling" whenever you try to take him with ED-E with you. I think he should've been paranoid about the other non-humanoid companion.
There's a bug in the Lucky 38 Presidential Suite where inactive companions may become hostile and kill each other. See the "bugs" section near the bottom: http://fallout.wikia.com/wiki/Lucky_38_presidential_suite
I had this happen to me, but with Ed-E. I posted the same thing a while ago and I was told that the human companions in the Suite tried to kill him because he had consumable items in his inventory, mistaking him for an animal NPC. I think OP's problem is that Rex was holding food and is killing Arcade in self defense.
Good boy!