Vouchers are permanent, run-long upgrades purchased from the shop. They do not take up a Joker slot and provide passive benefits that accumulate over time. These can include increased money from blinds, shop discounts, more rerolls, or even extra Joker slots. Vouchers are often expensive but are excellent long-term investments. Prioritize buying them early in a run if they align with your strategy, as their benefits will compound over many blinds.

Common Voucher types:
- Blank Voucher: +$1 per blind.
- Holographic Voucher: Shop items are 10% cheaper.
- Foil Voucher: +1 shop reroll per shop.
- Polychrome Voucher: +1 Joker slot.
- Negative Voucher: Start with -1 Joker slot, but gain a powerful bonus.