Rulestage runs minimum and maximum quantity, order value, per-customer limit, capacity and signed-in-customer rules inside Shopify's checkout validation. Before you publish, run any cart, buyer and country through the simulator and see which rule wins. Contradictory rules block publishing. Every publish is a version you can roll back. Saved scenarios show what a change would do. When a shopper reports a block, load that cart against the version that was live and read the reason.
Limit quantity per customer with quantity selector button...
"Notify & limit orders; manage waitlists, restocks, and...
Validate checkout information to prevent unexpected checkouts...
Automate time-limited sales and pre-launch announcements