Descend a dungeon where every door is a times-table product, answer to drop a floor, miss and the guardian closes in, and draft relics on the way down.
Each door shows a multiplication problem; key in the product to open it and descend a floor. There's a short speed window for a bonus, so answer quickly. Miss and the guardian closes in, costing you health. Between floors you draft relics that bend the rules in your favour. Facts you get wrong come back around more often, so the dungeon naturally drills the tables you haven't mastered yet.
Tunnel Tables turns multiplication-fact practice into a dungeon crawl that spaces out your weak facts so they get the most repetition.
Keying in products to open doors is drill on the multiplication table, the oldest piece of arithmetic memorisation there is — versions survive on Babylonian clay tablets.
The original structure is that facts you get wrong come back, and relics drafted between floors bend the rules.
Returning the missed facts is the part that matters. Plain drill spends most of its time on what you already know; resurfacing exactly the products you failed is spaced repetition applied to times tables, which is the difference between practising and improving.
Tunnel Tables is an original, free browser game that turns multiplication-fact practice into a relic-drafting dungeon crawl, spacing your weak facts for review. No download required.