What is trample?Edit
Trample is an ability that is used when the creature attacks and is blocked by an opponent's creature. When a creature with Trample attacks and is blocked, any damage not dealt to the blocking creature goes through and does damage to the player.
Trample ability may only deal excess damage points to a player or Planeswalker if it is attacking.
Suppose a Terra Stomper (8/8 with Trample) attacks an opponent and is blocked by a Dross Crocodile (5/1). The Dross Crocodile is dealt 1 damage and dies. The remaining 7 life points in damage is dealt to the opposing player.
If the opposing player has a Planeswalker on the board, the attacking player may elect to deal this 7 damage to the Planeswalker instead of the opposing player.
If a 2/2 trample creature, like Graypelt Hunter*, attacks, and the opponent blocks with Summit Apes (5/2), both creatures die, but there are no excess damage points to be dealt to the opposing player.