Card rules · 2026-10-29
Does a Valid Hand Have to Contain a Set?
Under the thirteen-card grouping conditions used here, a set is not compulsory when valid sequences cover the entire hand. At least two sequences are required, including a pure sequence,…
Under the thirteen-card grouping conditions used here, a set is not compulsory when valid sequences cover the entire hand. At least two sequences are required, including a pure sequence, and all cards must belong to valid groups.
A hand with no sets at all
Consider these thirteen cards, with no designated wild rank:
2♥ 3♥ 4♥ 5♥ 6♥ / 7♣ 8♣ 9♣ 10♣ / 9♦ 10♦ J♦ Q♦
The group lengths are 5, 4 and 4. Every group consists of consecutive ranks in one suit. All are natural sequences, so the pure-sequence requirement is satisfied as well. Every card belongs to one group, and the total is thirteen.
There is no set of matching ranks. That absence does not invalidate the arrangement under the stated condition. The repeated nines and tens occur in separate sequences; they do not have to be pulled out and converted into sets.
Why “four groups” is not the same rule
A familiar illustration may use groups of 3 + 3 + 3 + 4 cards. That is one way to organise thirteen, not proof that every valid hand must have four groups. The 5 + 4 + 4 example meets the stated sequence condition without copying that layout.
However, the arithmetic alone is not sufficient. Three piles containing five, four and four unrelated cards would still fail. The group sizes describe the partition; rank order and suit establish whether the piles are sequences.
One pure sequence is not enough either
Now consider a different thirteen-card hand:
4♠ 5♠ 6♠ 7♠ / 3♣ 3♦ 3♥ / 8♣ 8♦ 8♥ / K♣ K♦ K♥
It has one four-card pure sequence and three sets. Every card is grouped, but the second required sequence is missing. Under the same declaration condition, this arrangement is incomplete. Adding more sets does not replace the missing kind of group.
These two hands answer opposite mistakes. The first shows that sets need not appear at all. The second shows that valid sets cannot compensate for too few sequences. Count the required group types as well as the cards; that is more precise than following a remembered picture of what a finished hand should look like.