Minion placement is not all that important for most of the game, but there are a few cases where it makes a difference. There are various spells or abilities that hit one minion and adjacent ones, and preventing those from achieving the maximum effect seems to be a good idea.
The only part I currently pay attention to is to always play my Faerie Dragon into the middle of my minions. This prevents spells that hit adjacent minions from being used optimally, as my opponent has to target one of the minions at the edge and can only hit two minions at once.
But I'm pretty sure that there are many more instances where minion placement can make a difference that I currently don't pay attention to. Are there any general rules on how to place minions most effectively? I'm interested in general principles that I can always apply, but also more specific cases like when playing against specific classes.
Best Answer
There aren't that many spell cards right now that take minion placement into consideration:
Spells:
Obviously, most of these are highly situational and its up to you if you want to allow 2 high value targets to take damage, or potentially lose a low value target instead.
The only one that really matters is Betrayal, where you don't want to place high attack minions next to each other to minimize damage. Like you said, Faerie Dragon is a great mid position card as is any other stealth creature. If you can force them to target an end position card, that's great but the likelihood of being able to maintain something like that for the entire game is very low.
Also, here are all the creature cards that boost adjacent minions: