Every game you play, you win free coins, even if you lose!
Winning a Game
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Win a game and you will rewarded with a number of coins.

• Win vs 1 Bot = 3 coins
• Win vs 2 Bots = 7 coins
• Win vs 3 Bots = 16 coins
• Win vs 1 Human = 5 coins
• Win vs 2 Humans = 12 coins
• Win vs 3 Humans = 20 coins

Finding a Gem
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Whenever you win a game there is a chance that instead of coins, you could find a rare Green gem, or an even more valuable, ultra-rare Red gem (worth 30 green gems). Gems can be used to trade for individual cards direct from the Library.
Losing a Game
If you lose a game, regardless of its type or number of players, you will always win a coin.
Twilight Dragon
This creature is deceptively dangerous. For a relatively low cost, this creature has high enough hit it is difficult to kill easily, and can do a surprising amount of damage while your opponent scrambles to deal with it. 
A good card to draw your opponent's easy kill options (fatal blow etc.) leaving room for even more dangerous options later to emerge with no answer...
Imperial Monk
when I first stepped on the scene years ago, when these stomping grounds was known as advanced fallen worlds, this was my favorite card. for a few res he can snatch any creature your opponent puts on the field, and he can do this for the entire game. find ways to protect him, and keep him on the field, and the game should be yours