Managing the Daily Grind: Best Uses for Coins
Coins are your primary tool for active progression. Since they reset every time you enter a new mine, you don't need to be overly precious with them—but you must be smart about where they go first to generate exponential growth.

1. The Golden Rule: Invest in Production First
When you start a new mine, the biggest mistake is immediately assigning goblins to the nearest rocks. Your first priority must be to increase your gold income. Without a steady flow of gold, you'll run out of resources to hire the goblins needed to clear harder rocks .

Prioritize the Forge: The Forge is your primary source of gold in the early stages of a mine . Use your early gold to double or triple its production immediately . This ensures you have a healthy "salary" coming in to afford new goblins.

Upgrade the First Mineshafts: As you unlock and repair them, upgrade the active Mineshafts as soon as the green upgrade button appears. These are your secondary income sources. A high-level Mineshaft will provide a massive boost to your passive income, funding the rest of your operations .

2. Don't Be Afraid to Spawn (and Merge) Goblins
Coins are used to summon new Level 1 Goblins. While the cost of summoning increases with each purchase, you shouldn't hesitate to spend gold here . The key is to merge them immediately. A single Level 3 Goblin mines faster than two Level 2 Goblins and takes up less space . Spend gold to spawn enough goblins to create a few high-level "foremen" to smash through the tough rocks.

3. Save for the Big Multipliers
When upgrading buildings, you'll notice a progress bar. Filling this bar completely triggers a massive multiplier to that building's production . Sometimes it's worth saving your coins for a few extra minutes to hit this milestone rather than spending small amounts on irrelevant upgrades. This "milestone boost" is where your income really spikes.

4. The Last-Minute Rush
If you're close to a gate and the timer is ticking, spending a little gold to spawn one more goblin or to merge your existing ones into a higher level can save you hours of waiting. Don't leave a gate at 90% if you can finish it now.

The Permanent Power-Up: Best Uses for Elixirs
Elixirs are the true test of your strategic planning. Unlike coins, they don't reset. You find them by smashing rocks, opening chests, and completing levels . Because they are rare, where you spend them determines your late-game potential.

1. The "Elixir Protection" Rule
This is the most important rule in the game: Never spend Elixirs on Common cards early on. The game will prompt you to upgrade anything and everything, but this is a trap.

Elixirs spent on the wrong cards are a permanent loss. You will not get them back . Focus solely on cards that offer a broad, long-term benefit to your mining strategy.

2. The Ultimate Priority: Forge and High-Speed Trolley
According to advanced guides and player experience, two specific Rare cards should consume the majority of your early and mid-game elixirs.

High-Speed Trolley (Rare): This is arguably the best card in the game. It increases the work speed of the Forge and ALL restored mineshafts . It impacts nearly every aspect of your production and is never a wasted investment.

Forge Card (Uncommon/Rare): As the Forge is your financial engine, any card that boosts its output or speed directly translates to more goblins and faster progression .

3. The Strategic Investments (Mid-to-Late Game)
Once your Forge and Trolley are at respectable levels, look at these impact cards:

Lucky Charm (Rare): Gives your goblins a chance to deal critical damage. This can significantly speed up the destruction of high-level rocks and gates .

Iron Pickaxe (Rare): Increases the gold you get from smashing rocks. While the benefit is steady, it is considered a lower priority than production cards because it doesn't compound as effectively .

Crusher Tuning (Rare): Upgrades the speed of the bonus Crusher Truck mini-game you play between mines. Since this mini-game is a primary source of Elixirs and Gems, making it faster yields more premium rewards over time .

4. What to Ignore
Avoid dumping elixirs into cards that offer niche or one-time benefits early on. For example, Mysterious Barrels buffs only the gold found in the occasional barrel drops, which doesn't compare to the consistent output of the Forge . Similarly, only upgrade cards for Mineshafts you aren't using if you have elixirs to spare—which is usually never in the early game.