How to Get Cores in Drill to Earth's Core — Every Source Ranked

The short answer

Cores are the lobby currency. They buy classes, book items, and can be exchanged for Coins. There are exactly four sources, split between the lobby and the run:

That is the whole list. There is no codes button and no promo codes in this game, which is worth stating plainly because a lot of pages and videos promise free Cores for a code — they are describing a different Roblox title. If you want the class prices those Cores unlock, the all classes page has them.

Achievements: the biggest one-time payout

Achievements are Roblox badges awarded for specific tasks, and each completed one pays Cores. You reach them from the Achievements button in the lobby or a board inside a town.

Two things stand out. First, Mine Ruby at 175 Cores is by far the largest single reward, and it is a mining task rather than a combat one. Second, several of the 30-Core badges cost you almost nothing: joining the group, playing with a friend and coming back a second day are all free Cores for actions you were going to take anyway.

The death badges are worth a mention because they pay well for something you cannot avoid — 100 deaths is worth 85 Cores, which is more than a diamond node.

Chests: the repeatable income

Chests are found in structures or bought in the lobby, and they reward every player nearby with Cores plus items. Two multipliers stack on them:

Chest tier. Wooden is 1x, Golden is 2x, Diamond is 5x, Void is 10x.

Depth. Chests gain 0.2 Cores for every layer you have broken during that run, so the same chest is worth dramatically more at 50,000 m than at 2,000 m. Higher-tier chests also multiply that depth bonus.

The practical conclusion is that chest value is a reason to go deep rather than to farm shallow. A run that reaches the Toxic Layer and opens a few Diamond chests beats several short runs with Wooden ones.

One warning: Wooden Chests have a chance to turn into a Mimic when opened. A Mimic chases the player while charging an explosion for 10 seconds. It can be attacked, and the Steal Vitality drill upgrade can drain HP from it, but it is immortal — so treat it as a timer, not a fight.

Boss walls: small, flat, and rising

Breaking a boss wall pays a flat 10 Cores per layer, and the amount increases steadily as you go deeper. The Grass Boss Wall is the exception: it rewards no Cores at all.

This is the most predictable Core source in the game and the least exciting. It will not fund a 30,000-Core class on its own, but it is free income attached to progress you were already making — every layer you clear for the first time hands you a small permanent bump.

What to spend Cores on

Cores buy three things: classes in the Academy, item bookings in the lobby, and Coins via exchange.

For most players the priority is straightforward. Miner at 100 Cores is the only cheap unlock and it funds everything after it. From there the best classes tier list explains why Driller and Lucky Looter come next, and the beginner guide covers your first hour if you have not spent anything yet.

If you are specifically saving for Reaper, the Reaper guide covers what the 10,000 Cores actually buy you. And once you are descending regularly, reaching 100 KM is the run plan that maximises both Cores and Coins per hour.