Redevelopment of Lost Cities, first published with altered rules as Keltis, and then published by Rio Grande as Lost Cities: The Board Game with Knizia's original rules and theme.
Reiner Knizia: "The original version that we developed is exactly what Jay [Tummelson, owner of Rio Grande Games] has now published [LCBG]"
Primary differences between Lost Cities: The Board Game and Keltis:
1. In LCBG you play 3 rounds, scoring at the end of all 3 for the monuments you collect. (Normal scoring occurs each round.) In Keltis, you only play 1 round, and score everything each round. This is not just a rule difference, as the scoring is different for the monuments/stones based on the number collected.
2. In Keltis, you may play your cards in either order, descending, high to low, or ascending, low to high. In LCBG, you must play in ascending order.
Note: the rules for LCBG have the Keltis rules as variants, and have the board elements necessary for #1 above. Keltis does not have the rules nor board elements to play LCBG.
Kosmos (Keltis publisher) changed the card play to ascending and descending order to lower the luck level and add balance to the game.
Kosmos changed the theme to fit in with other Kosmos abstract game series.
There are more differences, which are non-substantive. Lost Cities: The Board Game has a different-looking board, tiles and figures (meeples) to connect with its predecessor. Card-play in descending order is an optional variant in this edition. The numbers have been multiplied by 5 to strengthen the relation to the card game, and instead of a scoring track you collect your points as golden coins.