In Templari, players take on the role of members of the Order of the Temple who have discovered part of the Templar treasure. Instead of donating this to museums, they decide to organize unusual auctions amongst themselves to distribute the spoils.
The innovative bid mechanism is that players cannot bid a number whose "ones" digit matches the number on any card they have previously won. Thus, if you have cards showing "2" and "4", you cannot bid 2, 4, 12, 14, 22, etc. What's more, when someone wins an auction, the money is paid out to those owning a card whose number matches the "ones" digit of the winning bid. Thus, while you need to acquire cards in order to win the game, you don't want to enrich your opponents too much.
Templari differs from the earlier releases Don and Serengeti in that the game has a maximum count of five players, all players start with twelve coins, and in each round players bid on lots of exactly two cards (whereas in earlier versions, the lots would have one, then two, then three cards, then back to one).