Muligan system needs work.

Most of the time if you throw back a few cards its fine but when you are throwing back just one card the system fudges up. The chances are insanely high that you will end up getting the exact same card back if you only muligan one away. Over many many games I have tested it and like close to 80% of the time you get the same exact card back. Unless of course you only have the one. But if you have two there is a good chance you will get it back. If you have 3 its damn near a guaranty. If you have three don't even bother trying to muligan it.

Oh and if it does get you something different you can bet that card will pop back up within the next one or two draws anyway.  

I have the same feeling. I always thought it is bad luck. I put away my Riptide Rex and of course I will draw a new one immediately.

But a mechanic which would prevent drawing another one of the cards you put back in the deck might be a not so good idea either. 

If it really is the randomizer that is broken, that may be an easy fix. If it really is bad luck... well... it's bad luck. 

Confirmation bias with no actual statistics whatsoever.

It doesn't need a rework at all.

Currently, LoR does have random mulligans, since they would definitely have informed players if it wasn't random.

However, why doesn't LoR make opening hands less random? What if LoR implemented a rule change that when you mulligan a card away you will always draw a card that costs less than it if possible? Given that LoR is online, I see no reason why they would keep Mulligans random when they have the ability to bias them to help the player. They could also do something like make it so that you never get a 7+ cost card in your opening hand, since it doesn't feel particularly fun to get a bricked out hand and be unable to play.

Quote From CursedParrot

Currently, LoR does have random mulligans, since they would definitely have informed players if it wasn't random.

However, why doesn't LoR make opening hands less random? What if LoR implemented a rule change that when you mulligan a card away you will always draw a card that costs less than it if possible? Given that LoR is online, I see no reason why they would keep Mulligans random when they have the ability to bias them to help the player. They could also do something like make it so that you never get a 7+ cost card in your opening hand, since it doesn't feel particularly fun to get a bricked out hand and be unable to play.

I think just sending the cards you muligan out to the bottom of the deck or somewhere in the middle maybe best.

As sometimes you want at least one large spell for turn 3 or 5. Like for example turn 5 Fiora + Unyielding Spirit.