Welcome, welcome 
Today, I had a bad situation. I had 18 dead Volatile Skeletons when Opponent (Paladin) had 7 immune minions because he used The Jailer. I used Kel’Thuzad, the Inevitable to explode most of my Skeletons. But instead of targeting only one vulnerable target - Hero - they targeted immune minions. That have no sense for me. Can you, Blizz, change that mechanic? There are some cards, like Rune of the Archmage, which can dodge the immune targets.
Best wishes,
Danelar
That’s because Rune of the Archmage doesn’t cast spells with random targets, but casts random spells. Immune characters can’t be targeted by spells, but spells and effects with random targets don’t need to target. (Hope I make sense.)
Thanks for your answer. Yeah it’s make sense, ofc. But still, changing that mechanic will be better idea, I guess.
Bisous,
Danelar
that would mean changing skeleton to targeting effects…is a dearthrattle and you cant take action on your opponent turn to choose targets
I think he means changing the “damage random enemy” mechanic to exclude immune enemies, not changing skeleton to target.
Yes, indeed. I will have more sense 
They aren’t going to change it because that is the way they intend it to work.
What they should have, is information available to understand how game mechanics work without having to try everything out. Like a FAQ for each card.
But the game engine the way it is now won’t be fixed because it will cost too much.