Playing Null

Null throws out everything else in Skat: no trump, no Augen to bank, just one job. You are the declarer and you have to lose every single trick, because one trick costs you the whole contract. The cards run 7-8-9-10-Jack-Queen-King-Ace, each Jack stays in its own suit, and the Ten is no longer a high card here: it sits between the Nine and the Jack. Every card you play, lead or follow, is aimed at the same thing: staying under what is already on the table.

Read the official rule on Null's card order.

The one lead you might get

You're the declarer in a Null game and you're sitting in Vorhand: you lead the first trick, and that stays the only lead of the whole round. Whoever wins a trick leads the next one, and winning one is exactly what you must not do. A card is safe only when two things hold at once: nothing lower is still out in its suit, and at least one higher card still is. The Seven of Diamonds7 gives you the first half for free, because nothing sits under a Seven: every defender holding Diamonds has to play over it. Miss either half and it goes wrong. Hold the Eight of Hearts8 while the Seven of Hearts7 is still out, and one defender ducks with the Seven, the other is out of Hearts and discards, and your Eight takes the trick. A suit nobody else has left is the same trap: both of them discard, your card is the only one of its suit in the trick, and the trick is yours. That is not good news, that is the contract gone.

Ducking under

You're the declarer in a Null game, someone else has led, and you can follow suit. Then the first question is simple: does one of your legal cards stay under the highest card of the led suit already on the table? If it does, play it. Say Hearts were led with the Ten of Hearts10, the next player put the King of HeartsK on it, and you hold the Nine of Hearts9 and the Ace of HeartsA: the Nine is the card, because it stays under the King, while the Ace would take the trick. Only what is already on the table counts. Once a higher card of the led suit lies there, the trick can no longer come back to you whatever the player behind you does: the card that beats you stays put. Ducking costs you nothing and keeps you exactly where a Null declarer wants to be, still on zero tricks.

Dumping a liability

You're the declarer in a Null game, someone else has led, and you have no card of that suit left, so you're out of it and free to throw anything. That is the one chance in the round to take work off your own hands. The first question is not which card leaves, but which hand is left behind: throw the card that leaves the rest of your hand safest. When that comes out level, the stranded card goes, the one with the fewest cards still out above it, because that is the card with the least room left to duck. Hold the Ace of ClubsA and the King of SpadesK while the Ace of SpadesA is still out, and the Ace of ClubsA goes: the King can still slip under the Ace of SpadesA later, the Ace under nothing at all. Hold both in one suit instead, the Ace of ClubsA and the King of ClubsK, and they are equally stranded, so the Ace only goes first because it is the higher card.

When you're forced

You're the declarer in a Null game, you have to follow suit, and none of your legal cards stays under what is on the table. Say Diamonds were led with the Seven of Diamonds7, and all you hold is the Nine of Diamonds9 and the Ten of Diamonds10: both of them go over. Playing last, that settles it, the trick is yours and the Null is gone. Playing earlier it is still open, because the player behind you has to follow the suit too and can take the trick off you. Either way, play your lowest card, the Nine here: it leaves the last player the best chance of getting over it. The loss has no cheaper or dearer version anyway, because Null counts no Augen at all and one trick costs the whole contract. Once it has really fallen there is nothing left to protect, so just play the hand out.