Collect 10,000,000,000 studs. (Single Player Only)
To unlock this massive achievement, you’ll need to earn 10,000,000,000 studs. Single player only achievement don't go for this in Co-Op.
Finding the x2, x4, x6, x8 and x10 red bricks will help you out tremendously. Collecting the all will earn you a x3840 multiplier for every stud collected. Remember, all of the Mithril items to get the multipliers need to be forged first, so you'll need to find the Blacksmith.
Click HERE for a guide on how to unlock multipliers.
How to Unlock the Blacksmith:
You will need Ori and Sam or Fili for this. Suggest doing this after completing the story. First, you need to travel to Bree. The Blacksmith Shop should show on your map if you set it as your destination or look for the forge sign. Talk to a lady with a beard. The quest is called “Smithy in Peril.” She wants you to find her husband. Search the caves around Weathertop for the missing Blacksmith. The cave is right next to Carpenter’s Quandary. It should show on your map after you’ve talked with her.
Once inside, you’ll see the Blacksmith jumping up and down. You need to do a buddy-up smash attack on a wall and then use Ori to shoot a target with his slingshot. Next, use Sam or Fili to plant a mushroom jumper. Jump up and turn the green lever to raise the platform (make sure you turn it fully). Exit the cave head back to Bree. You can now begin forging Mithril.
Select a design piece you have found to forge. Displayed at the bottom of the screen in the required LEGO loot you need to craft each item.
Turn on the multipliers in the Extras menu if you have them. Travel to Bree. There will be a Ghost looking door only Bilbo can smash. It's between the Prancing Pony and the Blacksmith.
Use Bilbo and hit to activate the ring and smash the door there. There should be three blue studs and a purple one in the corner. Come back out and go into the Blacksmith shop. Now come back out and the ghost door should re-spawned. If you get the Stud Attract red brick you can farm this area a lot quicker. Using Beorn's Bear form it will make this a faster process. Rinse and repeat until satisfied.