Previous Versions can be found here.
Break is an Integrity deck specific effect card. When used, it allows you to send one of the cards on your board back to your hand, just like Doggo.
However, Break will also give you 20% of the monster's cost in gold, meaning that it will be a free card when used on a 5-9G monster. It will even give you extra gold when used on a monster with a cost of 10+.
This resets their stats, so it's best used when wishing to gain more monsters through the Magic effects of cards like So Sorry, Alphys or Onion San, returning and replacing mid-priced silenced monsters such as Igloo, Mad Dummy or Sans as well as recovering and/or reusing powerful monsters like Papyrus, Undyne or Asriel Dreemurr.