One of the earliest (and most broken) CCGs was Spellfire. One of the reasons it was so broken is that there was no concept of a 'casting cost', so the most badass card could be put into play for the same cost as a piece of crap card.
The Caravan:
Play only between two players' turns. The player of this event can take a turn immediately. Afterward, play resumes where it left off.
Good Fortune:
The player of this card draws five cards immediately.
Transformation!
All players must discard their hands immediately and draw five cards.
In Spellfire, you could only use one copy of each card in your deck, but you can see how overpowered some of the cards in that game were in spite of that.
Star Trek:
Raise the Stakes: Your opponent must forfeit the game OR agree the eventual winner may randomly select and keep one card from loser's 60-card deck. (Cumulative)
If you're going to make an overpowered cross-game deck, you might as well jank as many of your opponent's cards as possible. Also had no 'casting cost' due to Star Trek game rules, but because of card type, only one can be played per turn. There is no limit to how many copies of a card can be in your deck in this game.
Magic: the Gathering:
Demonic Attorney:
http://gatherer.wizards.com/Pages/Card/Details.aspx?multiverseid=58Remove Demonic Attorney from your deck before playing if you're not playing for ante. Each player antes the top card of his or her library.
Make them concede the game or everyone adds another card to the ante. You do want to steal your opponent's nymphs, don't you? And not just in the game, but from their COLLECTION!
Temporal Extortion:
http://gatherer.wizards.com/Pages/Card/Details.aspx?multiverseid=126814When you cast Temporal Extortion, any player may pay half his or her life, rounded up. If a player does, counter Temporal Extortion. Take an extra turn after this one.
Because 50 life is a lot more than 10 life
Plus extra turns are the r0xx0r. Would cost 4
in Elements terms to play.
Time Walk:
http://gatherer.wizards.com/Pages/Card/Details.aspx?multiverseid=131Take an extra turn after this one.
Because we still need more extra turns. It's not cool if the opponent actually gets to do anything. Hard to say which element corresponds closest to Blue in magic, but probably Aether, so it costs 1
+ 1
to play.
Blood Tribute:
http://gatherer.wizards.com/Pages/Card/Details.aspx?multiverseid=170995Kicker—Tap an untapped Vampire you control. (You may tap a Vampire you control in addition to any other costs as you cast this spell.)
Target opponent loses half his or her life, rounded up. If Blood Tribute was kicked, you gain life equal to the life lost this way.
Again, because 50 life is more than 10 life. (half) Better yet, Elements even has Vampires, so you can pay the kicker cost! :p Costs 2
+ 4
Shahrazad:
http://gatherer.wizards.com/Pages/Card/Details.aspx?multiverseid=980Players play a MAGIC subgame, using their libraries as their decks. Each player who doesn't win the subgame loses half his or her life, rounded up.
Because... LOL. 'nuff said. Costs 2
. If anyone here plays Magic, did they ever come across the shahrazad deck? Shahrazads, forks, miraris, timetwister, etc... If you don't know what I'm talking about, you really do NOT want to know...