These terms apply to purchases made through the Duelist Upgrade page on Undermax. They supplement the product license terms and privacy and refund policy. Review each selected product's itch.io page for its content, compatibility and any additional requirements.
Account and eligibility
Sign in through official itch.io authorization before reviewing or paying. We check the product identifiers in your account's owned keys and ownership entitlements, including eligible bundle ownership, and compare them with purchases already recorded by Undermax. We do not offer a product that our current checks show you already own or are buying in another order. If ownership cannot be verified, checkout is unavailable until the connection is restored. Delayed provider updates or a license attached to a different account may require help from support. Expansion Packs require Card Duel System. You may select an Expansion Pack only when this itch.io account already owns the core system or when Card Duel System is included in the same order. You must be at least 18 and legally able to contract, or have a parent or legal guardian complete the purchase.
Collection discount
One eligible product receives 10% off; two receive 15%; three or four receive 20%; five or more receive 25%. Buying every currently available missing Card Duel product in one order receives 30% off when at least two products are available. Out-of-stock products are excluded from the current completion tier. This completion tier applies to the products in that order, including Card Duel System if it is missing. Products you already own are not charged again. New Expansion Packs can join the eligible collection when published and stocked. Discounts cannot be combined with Friends or other offers. The current product price, availability, discount and total are confirmed before payment; an estimate on the collection page is not a locked quote.
Payment and delivery
Prices and payment are in USD through PayPal. Your provider may apply exchange rates or other charges. You must enter and confirm a valid email for the receipt and personal access links. We associate the order with the itch.io account ID used at checkout and save the order, amount, selected products, PayPal reference, delivery links and accepted terms in Purchases. A successful payment supplies personal digital links, not physical goods or a subscription. An order email is not a tax invoice unless explicitly identified as one.
Payment alone does not add products to your itch.io library. While signed in to the purchasing itch.io account, open each personal link and complete its claim on itch.io. You can then use Sync licenses in My account. Keep the links private. If email delivery fails, the links and receipt remain in Purchases after payment confirmation. Contact support if access or a claim fails.
License and refunds
Card Duel System and Expansion Packs are for RPG Maker MZ and may have version or parent-product requirements. RPG Maker MZ and other separately sold software are not included unless a selected product says so. By requesting immediate digital delivery, you acknowledge that a change-of-mind withdrawal right may end after supply starts where the law permits. Digital purchases are normally final. This does not remove mandatory remedies for defective or undelivered products, or rights under applicable law and PayPal's process. See the refund policy for requests and exceptional cases.
Privacy, issues and support
Undermax uses the minimum itch.io permissions required to identify your account and verify owned Card Duel products. We do not ask for your itch.io password. We store account, order, payment, delivery and consent records for operating the service; PayPal receives the amount, item names and order reference, but not your personal claim links. By using this service, you acknowledge the account, payment and security processing needed to operate it. Optional account activity insights require a separate choice and can be changed in My connections. Review the privacy notice and account insights notice. If payment is interrupted or its status is uncertain, check the existing order before attempting another payment. For a missing item, duplicate charge, account mismatch or refund request, contact [email protected] with your order reference or use the Support Portal.