Luck and rolls in Build and Kill Zombies

The game description never mentions rolling. The shop is built around it.

The evidence

Of four paid items, three concern rolls: permanent luck at two multipliers, and a faster roll. A developer does not build a two-tier permanent upgrade, priced apart, around something peripheral. Pricing the 4x tier well above the 2x tier also implies luck scales in a way players can feel — otherwise the upper tier would not sell.

What is not established

• What you roll for. Parts and weapons are the obvious guess; nobody has shown a roll screen.
• Whether there are rarity tiers, and what they are called.
• How luck changes the odds — whether 2x means twice the chance of a top result or something else.
• Whether rolls cost cash, a separate currency, or time.

Guides that publish rarity tables for this game do not say where they got them. We are not repeating them.

The prices and exact wording are on the game passes page.