In most trading card games like Magic or Hearthstone there's something called "card advantage".  Basically whoever has more cards in play has the advantage.  I'm designing a game where the mechanics incentivize the exact opposite.

There are three ways I plan to do this...

Some cards have effects that are more powerful when your hand is under a certain size. 

Other cards have effects that randomly chose cards from your hand to alter them, by limiting the size of your hands, you can weed out unfavorable results.

Lastly, "manna" the game's card currency generates in real time, the more cards you have in your hand the slower manna regenerates.

What do you think?  I would love feedback or suggestions.

I think if you have "less" cards in deck is mean you have "more" effect (something like more ATK more DEF or more rare cards in next random draw phase) is good for your game design