The opposite of vulnerable is invulnerable, meaning not susceptible to harm or attack.
Achilles was supposed to be invulnerable.
Another way to say invulnerable is untouchable. For example: The man with the big muscles thought he was invulnerable. .
invulnerable, indestructible, unconquerable, unbeatable, indomitable, unassailable; impregnable, inviolable; informal bulletproof.
Arrogant people appear to be invulnerable to criticism, but it is just a facade.
Vulnerable.
They are invulnerable to fire.
give the unit/building or whatever the invulnerable (neutral) ability
Heel
You press "edit options" and then find your player and make him invulnerable by putting 2x overshields or more.
"incapable of being wounded, hurt, or destroyed."
In WW 1, the armor on tanks was not THAT thick, and a heavy machine gun with armor piercing ammuntion COULD disable a tank. They were NOT invulnerable.