If your opponent has only Defense Position monsters on the field, you can attack directly with "Rocket Jumper", but if your opponent has a Spell or Trap Card, you cannot attack directly with "Rocket Jumper".
If your opponent has only Defense Position monsters on the field, you can attack directly with "Rocket Jumper", but if your opponent has a Spell or Trap Card, you cannot attack directly with "Rocket Jumper".