The ladder

Eight ores, seven pickaxes. Each ore makes the pickaxe with the same name, and each pickaxe survives each floor more often and is allowed deeper than the one before it. Deeper floors hold bigger veins.

Ore		Rarity	Pickaxe		Forge cost	Pays per pick	Goes to	Timer
	Rock	junk		Bronze	licence	25	shaft 3	30 min
	Copper	common		Copper	60	25	shaft 4	29 min
	Iron	uncommon		Iron	380	25	shaft 6	28 min
	Silver	rare		Silver	1,250	65	shaft 8	27 min
	Cobalt	epic		Cobalt	3,750	190	shaft 10	26 min
	Titanium	legendary		Titanium	10,000	500	shaft 10	25 min
	Mithril	mythic		Mithril	25,000	1,250	shaft 10	24 min
	Adamantite	divine		Adamantite	75,000	3,750	shaft 10	23 min

Forge costs are in INGOT, on top of the twenty lumps. Pays per pick is the average INGOT a pick brings up, give or take 40%. Timers are the base for one pick before your level knocks some time off, and each pick lands a couple of minutes either side of it.

What each pickaxe finds

A pickaxe mostly finds its own ore, with a decent chance at the next one up and a slim chance at the one after that. Bronze pulls copper about three lumps in four. Copper finds iron about one lump in six. From iron onward the next tier shows up about one lump in seven, so it's roughly thirty picks per upgrade. Runs in the shafts drop a lump too, which helps.

Entry and veins

Going down costs a tenth of your pickaxe's forge price, and never less than 125. Veins scale with the pickaxe: a copper vein starts around 135 INGOT, an adamantite vein around 5,000, and both get bigger the deeper you find them, up to four times at shaft 10. Your chance of hitting a vein goes from one in four on the first floor to two in three on the tenth. So does the chance of a collapse, which is why the pickaxe matters.