Blizzard has been knocking it out of the park recently when it comes to single player content for Hearthstone.

The last two expansions – Kobolds & Catacombs and The Witchwood – featured single player modes that let card slingers test their mettle against AI bosses. The Dungeon Run from Kobolds and Catacombs is still a great way to get to grips with the mechanics of Hearthstone and Monster Hunt from The Witchwood introduced four new heroes with special talents.

For the latest, The Boomsday Project expansion Blizzard is adding more single player content to the game in the form of The Puzzle Lab.

“The spirit of The Boomsday Project you’ll be doing something a bit more experimental, puzzles” says game designer Giovanni Scarpati. “When you enter Dr. Boom’s Puzzle Lab you’ll be met with a screen similar to those of previous adventures. Each “lab” contains one of four different puzzle types.”

These puzzles include: Lethal, Mirror, Board Clear and Survival. Unlike Monster Hunt or Dungeon Run however, players will be able to switch puzzles at any time.

Each lab contains eight puzzles. Hearthstone lead UI designer Max Ma says that during testing this felt like the right amount of content for a play session. That said, players are able to take a break from a puzzle at any time and can pick the run back up later.

The UI designer also revealed that the “End Turn” button will be replaced with a reset button so that having to retry a puzzle isn’t a bore.

“The puzzles ramp up in difficulty as you make your way through the labs but the most difficult puzzles of all are against Dr. Boom,” says Scarpati.

It seems as if – like with The Witchwood – you’ll need to finish all of the puzzles before you can face Boom but that’s unclear at this stage.

The Puzzle Lab opens next week on 21st August and will be available to all players for free.

Even if single player content isn’t something you enjoy you’ll want to log in to Hearthstone when they launch as you’ll net yourself three The Boomsday Project packs for free.

You can check out the Hearthside Chat about the Puzzle Lab below.