Derby is a horse race game played with cards. The full game includes some rules for betting, but these are rather rudimentary (the included gaming money is of best quality though - ASS is a famous playing card manufacturer in Germany).
The deck for the race contains 66 cards plus 6 horse cards. Each player chooses a horse. There are 11 cards in the deck for each colour/horse: 1,1,2,2,3,3,4,5,6,7,8. Each player has 7 cards in his hand and each turn he draws a new card, places a card on the table (if possible) and finally discards a card.
Placing cards on the table is only possible with cards of the own color. The first player, who manages to lay down all 8 cards (from 1-8) in the correct order, wins the race.