Crystal Depths collapse and charms guide: when should you collapse?
When to collapse your mine in Crystal Depths, how Echo Stones are calculated, and whether to save them or spend them on charms. Advice by play style.
In Crystal Depths, every mine slows down eventually. At that point, collapsing it and starting over is the way to progress much faster in the long run. This guide explains how collapse works and how to get the most out of your Echo Stones. If you're just starting, read the beginner's guide first.
What does a collapse do?
Once you've mined a total of 10 billion crystals in a mine, you can collapse it from the "Collapse" tab. A collapse resets:
- your crystals,
- all producers and upgrades,
- the layer you reached.
What stays: Echo Stones, your charms, achievements, stats and settings.
How many Echo Stones do you get?
The formula is simple: divide what you mined in this mine by 10 billion, take the square root and round down.
| Mined in this mine | Echo Stones |
|---|---|
| 10 billion | 1 |
| 40 billion | 2 |
| 90 billion | 3 |
| 250 billion | 5 |
| 1 trillion | 10 |
Because of the square root, each new stone costs more than the last. The Collapse tab shows how many stones you'd get right now and how much more you need for the next one.
Save or spend?
This is the real decision in the game. Every unspent Echo Stone boosts all output by 3%. You can also spend stones on charms, but a spent stone no longer gives that bonus. So every charm means giving up a little output in exchange for a permanent ability.
| Charm | Cost | Effect | Output it costs you |
|---|---|---|---|
| Hard Pick | 2 | Tap ×3 | 6% |
| Ready Crew | 3 | Every new mine starts with 10 Pickers | 9% |
| Lasting Hum | 4 | Resonance meter drains at half speed | 12% |
| Deep Sleep | 5 | Offline earnings 50% → 100%, cap 8 → 24 hours | 15% |
| Haggler | 6 | Producer prices −10% | 18% |
Advice by play style
You check in a few times a day (most players): make Deep Sleep your first goal. It doubles offline earnings and raises the cap to 24 hours. For anyone who stays away for long stretches, it gives back far more than the 15% output it costs.
You play actively at the screen: Hard Pick is cheap and strong. Tap upgrades add a share of your per-second output to each tap, and Hard Pick triples all of it. If you trigger Resonance often, Lasting Hum helps too.
You collapse very often: Ready Crew speeds up the first minutes of each new mine, but the effect is short-lived. It's only worth it if you play very short mines.
Don't make Haggler your first charm. A 10% discount doesn't win back the 18% output those 6 stones would give. Consider it once you have lots of stones.
If you're unsure, this is enough: let a few stones pile up before buying charms. Early on, every stone is 3%, and that compounds over several mines.
When should you collapse?
There's no single right answer, but this rule works well:
- First collapse: instead of collapsing right away for 1 stone, it's usually better to keep going until 2 stones (40 billion). Your first mine grows fast, and going from 10 to 40 billion doesn't take long.
- After that: collapse when the stones you'd gain are at least half of the stones you already have. For example, with 6 stones, collapse once you can earn at least 3 new ones. If the gain is smaller, the mine is still productive, so keep going.
- If the mine seems stuck: when the next layer and the next stone are both far away, collapsing and starting stronger is almost always faster than waiting.
Achievements are permanent too
A collapse doesn't erase achievements. There are 36 in the game, and each one gives +1% to all output. Some, like "First collapse" and "5 collapses", reward collapsing itself. You can see which achievements you're close to in the "Quests" tab.
Quick summary
- Go to 40 billion (2 stones) for your first collapse.
- Check in now and then? Deep Sleep first. Play actively? Hard Pick first.
- Leave Haggler for last.
- For later collapses, use the "new stones at least half of what you have" rule.