In Iberian Gauge, players invest in railroad companies, and then use each share of stock to build track for the company they invested in. The track is added in the order of the shares purchased, and laying track over rough terrain is more expensive. Players can lease track from other companies, but failing to add on to their rails will decrease the values of their stocks. The game ends after the final Build round, where players add up the value of their Shares. The player with the most money wins.

The game box comes with a game board, 110 wooden Locomotives, 60 Share cubes, 5 Player tiles, 5 Railroad Dividend disks, 5 Railroad Share Value disks, 5 Railroad Initiative tiles, a Priority Deal token, a Round Marker token, and 150 Currency cards. This game is for three to five players, ages 12 and up, plays in an hour, and retails for $29.99.

Capstone Games released Irish Gauge in 2019 (see "Capstone Games Launches Iron Rail Series with 'Irish Gauge'").