Sid Meier's Civilization: Beyond Earth will be free-to-play on Steam this weekend, beginning this evening at 6pm BST, 2K and Firaxis have announced.

During the free-to-play period, players who participate will have until 6pm Monday to purchase Civilization: Beyond Earth or the Civilization Beyond Earth: The Collection at more than 10 per cent off, while retaining their in-game progress.

In addition, existing players who pre-purchase the Rising Tide expansion will also receive a 10 per cent discount.

Rising Tide will expand Beyond Earth to new frontiers on the planet's surface and across its seas, adding more choices and diplomatic options. New aquatic gameplay will explore the oceans, extending the play space, while an overhauled diplomacy system promises additional layers of dynamic choices.

Sid Meier's Civilization: Beyond Earth - Rising Tide will launch October 9.

Source: 2K