CastleMiner Z Tips and Tricks
Each entry below is one mechanic, what it costs you, and the update it was last checked against. Filter by category or difficulty to narrow the list, and use the anchor beside any heading to link straight to a single tip.
Dragons
#The Undead Dragon force-spawns at 4,000 blocks on odd days only
It tracks the day counter and not your position, so bring a Bloodstone LMG or a laser assault rifle before the odd day arrives. Being underground when it spawns does not save you, and neither does distance from spawn.
Checked against 1.9.9.8
Tools
#The Bloodstone Pickaxe is the best tool and it is not unbreakable
Ten Bloodstone blocks and 3 Diamonds buy you something that mines around four times faster than Diamond and is the only pickaxe that handles Lava and Space Rock. Expect roughly two to three hours of real playtime before it wears out entirely.
Checked against 1.9.9.8
Weapons
#An energy weapon's color tells you its trim, not its power
Iron makes red, copper green, gold pink, and diamond blue, and none of it changes the weapon. Players who call Red the top tier are reading the trim, so a Blue Laser Pistol is the diamond-expensive build and not a stronger one.
Checked against 1.9.9.8
Biomes
#Hell is 40 blocks down or 3,400 blocks out, whichever you prefer
Both routes reach the same biome, which means you do not have to make the long walk if you would rather dig. It brings lava pits, unique blocks, and enemies that hit harder and take more damage than anything on the surface near spawn.
Checked against 1.9.9.8
Bases
#The idle box has to be copper, iron, or bloodstone
Zombies dig through grass, dirt, wood, ice, snow, and sand, and the Red variant chews rock as well, so anything softer than metal comes down eventually. Light the chamber too, since skeletons only spawn in the dark, and it will hold for as long as you idle.
Checked against 1.9.9.8
#Going underground removes nothing by itself
Depth alone protects nothing. What keeps you alive is a sealed chamber, because an open cave system underground is still hostile territory and the zombies and skeletons down there path toward you the same way surface zombies do.
Checked against 1.9.9.8
Difficulty
#Walking 1,000 blocks raises your threat more than 20 days does
Threat scales by how far you travel from spawn, not by how long you have survived. That is the single most important thing to understand about the game: a cautious player who walks a long way is in far more danger than a reckless one who stays put.
Checked against 1.9.9.8
Bases
#A dragon fireball destroys sand and wood the moment it lands
That makes either one worthless as an outer wall on Hard mode however thick you build it. Use Bloodstone, Diamond Walls, Bulletproof Glass, Space Rock, or Space Goo for anything on the surface that you want to still be there tomorrow.
Checked against 1.9.9.8
Ammunition
#Bullets cost materials, so do not spend diamond on surface zombies
Crafting ammunition needs a constant supply, and a weak zombie dies just as well to iron or copper. Keep the diamond and bloodstone rounds for dragons and aliens, which are the only things that genuinely need them.
Checked against 1.9.9.8
Loot
#Gold Loot Blocks never appear in Endurance or Dragon Endurance
They are real and drop three items each, including laser rifles, a diamond LMG, bloodstone, and explosives, but they spawn underground and on sky islands in Survival, Exploration, and especially Scavenger mode. They are also not a Crash Site feature.
Checked against 1.9.9.8
Resources
#Trees never grow back, so logs are finite where you stand
Forest biomes do reappear as the world repeats outward, but that is a long expedition and not a renewable supply next to your base. Bank enough wood before you commit to a location, because there is no second harvest where you built.
Checked against 1.9.9.8
Achievements
#Only Endurance mode awards achievements, and solo is fine
Survival, Creative, and Dragon Endurance award nothing at all, which is the single most common reason players see no progress after hours of play. Solo Endurance counts perfectly well for the kill, craft, distance, and day achievements, so you do not need a lobby.
Checked against 1.9.9.8
#The time-played achievements are not broken any more
DigitalDNA patched them in August 2025, and Update 1.9.9.8 states plainly that entries like MinerZ Potato now accumulate and save correctly. The same update reduced out-of-memory crashes. Players who call them permanently broken last tested before that patch.
Checked against 1.9.9.8
#MinerZ Potato wants 100 hours, not one unbroken run
Progress carries across sessions and never resets on death, and that is what made the achievement reachable at all. Chip at it across normal play instead of planning one enormous dedicated run.
Checked against 1.9.9.8
Tools
#Make the Bloodstone Pickaxe your first goal underground
It will not last forever, but it mines fast enough that you spend far less total time replacing tools than you spend crafting it, and it is what opens up Space Rock. Everything else in the deep underground goes faster once it is in your hands.
Checked against 1.9.9.8
Weapons
#Both halves of an energy weapon come from Alien Crash Sites
You craft the guns from Space Goo and their bullets from Space Rock, and both materials are found there, which puts the entire top of the technology tree behind finding one. Nothing else in the world produces either material.
Checked against 1.9.9.8
Lobbies
#Host a passcode-protected lobby if you want to idle safely
It is a convenience now and no longer required. If you want to anyway, a locked Endurance lobby with yourself as the only player is the documented method, since a passcode keeps strangers from wandering in and ending the run.
Checked against 1.9.9.8
Saves
#Endurance cannot be saved, so a crash ends the run
There is no manual save at all in that mode, and disconnecting or closing the game finishes what you were doing. Since Endurance is also the only mode that awards achievements, every long attempt is a single unbroken sitting whether you planned it that way or not.
Checked against 1.9.9.8
Achievements
#The elaborate idling rituals exist because runs used to vanish
Closing or crashing the game reset the playtime counter for most of this game's life, and players reported losing progress at 30, 33, 89, and even 91 hours. That history is why so much surviving advice reads like a superstition, and it no longer applies.
Checked against 1.9.9.8
What to Read Next
- Enemies and Biomes. What actually scales difficulty, every dragon, and where Hell begins.
- Weapons and Tiers. The full crafting ladder, energy weapon trims, and tool durability.
- Game Modes. Endurance, Survival, Creative, and what each one does and does not track.
- Achievements. Which mode counts, and the timer bug that was finally fixed.
- Getting Started. Your first night, finite resources, and building somewhere safe.
- Multiplayer and Controls. Lobbies, passcodes, and playing with other people.