Konami just sent a notification in-game to all players that they're drastically changing the structure of Daily Missions. This is likely in response to combating the Gem exploit that would guarantee high-value missions by not claiming the old one. All the missions now reward exactly 40 Gems, and are as follows (all of them except the first are in Ranked duel):

  • Duel in Solo Mode 3 times
  • Summon 3 Monsters
  • Special Summon 5 Monsters
  • Win a game
  • Inflict 15.000 damage to your opponent
  • Destroy 5 cards
  • Declare 5 attacks with a Monster (the notes say 'to a monster', but this is likely a mistranslation)
  • Activate 2 Traps
  • Activate 3 Spells

The changes are supposed to go live about 9 hours from the when this article is published. Check your notifications in-game for an exact time.