Among card games, Skat is unusual because we know, more or less, when and, exactly, where the game began. Primitive Skat was developed around 1811 by residents of Altenburg, Germany. It is the descendent and melding of three other games, Sheepshead, Hombre, and Tarot (Tarok in the German spelling), which themselves derive from more remote ancestors.
Card games can be distinguished by their characteristics: One or more players, whether trumps exist, whether players act as partners or not and, if so, whether the partnerships are fixed or vary from game to game (alliance). The fundamental characteristics of Skat are that it is a: (1) point/trick game; (2) played by three players two of whom form an alliance against the third; (3) using a pack of thirty-two cards in which (4) the four Jacks are permanent highest trump.
If card games had bloodlines, that for Skat might look like the following:

Some games that are representative of each category are given in italics. To summarize the diagram, one could say that Skat is a trump game for several players (3) who sometimes act in temporary alliance as partners with the goal of capturing card points. This distinctive set of features is the result of a melding of the best features of several games, Hombre, Sheepshead, and Tarok, in particular.
Card games have the merit, compared to games of pure chance such as dice or games of pure strategy such as Chess, of mixing the elements of luck and skill. Luck gives any player the chance to win, but skill elements mean that better players will win more often. Among card games, these elements can be mixed in a variety of ways. The act of shuffling and cutting distributes the cards in a comparatively random manner. Games are then more or less strategic depending on the extent to which the lie of the cards can be determined and when. More strategic games provide more information sooner. This can be done a variety of ways: bidding, exposing cards, and shortened packs.
Some popular games and their characteristics along these lines are given in the table below.

Bidding conveys information. The extreme example of this is Bridge where the goal of the bidding is to convey to one's partner as precisely as possible the exact configuration of one's hand. In Skat, the bidding is by number so that the exact cards held are not always clear, but one gains information on the cards held and the intended game by where the bidding stops. More strategic games have fewer players. "Cutthroat" games such as Skat have only three and the soloist's full resourcefulness must be used to defeat two opponents.
In games of pure strategy such as chess, the opening positions are completely known. Card games are more or less strategic depending on the total number of cards and the percentage of them that are known at the start of play. The shorter the pack, the more quickly the lie of the cards can be determined in addition to those known in advance. Strategy is most effectively implemented from an offensive position. The purpose of trump is to change the offensive and defensive positions. Thus, the greater the proportion of trump, the greater the role of strategy.
The greater the latitude for altering the type of game played, the greater the number of strategic options. Selection of a trump suit as well as the goal of the game, points or tricks, all are important considerations. Point/trick games require greater skill than trick-taking alone. Skat offers even more choice by allowing either a point/trick or pure trick (avoidance -- Null) option. It also allows the choice of using the Skat (and having more information at the start) or playing without it for a higher score. Furthermore, like Bridge, but unlike Euchre, Skat allows the choice of trump, or whether there is any at all. Skat has sometimes been called the "Chess of Card Games" and for good reason. But, unlike Chess, there is always the thrill of picking up the Skat and finding something unexpected!
© 1995, John W. Sell