Yu-Gi-Oh! is simple: both players start with a set amount of Life Points, and the first player to reach 0 loses. Both players are able to summon monsters to do damage to one another, but they can also play or set Spell and Trap Cards. Some of these Spell Cards are far more powerful than others though, which is why some of them have been, or are currently banned in tournament play.
10. Graceful Charity
The card game has changed quite a bit since 1999, and one of the biggest changes is the fact that players are now incentivized to draw and dispose of as many cards as possible. This is the reason why Graceful Charity is banned, because it allows a player to draw 3 cards and then discard 2 of them.
This effect is over-powered because there are now too many monsters who gain ATK and DEF bonuses from the discard pile, but there are also a lot of other powerful monster effects that are solely dependent on the discard pile as well.
9. Cold Wave
Cold Feet is one of the card game's strangest cards because players are free to use it, despite the fact that its effect is more or less identical to Cold Wave, which is banned. When Cold Wave is activated, neither player is allowed to play or set any Spell or Trap Cards.