Weapons before luxury
The shop is where a run is won or lost. Your first purchase should be a second weapon that shares your first weapon’s tag.
A matching pair raises DPS more than any single item. Buy the third weapon before you spend on passive bonuses.
Defense when the run is fragile
If you are dying around wave 8 to 12, spend the next visit on Armor, Dodge or Max HP. A dead character deals no damage.
Do not skip defense to chase a fourth weapon. The wall at wave 10 punishes a loadout with no survival stat.
Items that stack your tag
Passive items are strongest when they echo your build. An item that adds Melee Damage helps a melee build; it wastes a slot on a ranged one.
Buy items that fill a gap, such as Lifesteal when you fight in a crowd, rather than items that repeat a stat you already have.
Rerolls and discipline
Reroll only when the board offers nothing for your tag. Materials spent rerolling are materials not spent on weapons or defense.
Walk away from a bad shop with your materials if nothing fits. Saving them for the next visit beats a weak purchase.
Where to go next
Read weapons by class to pick tags that match. Then see items and upgrades for how passives stack.