noun
useless card; worthless card
In karuta, a card that has no value for scoring or gameplay.
See also: カルタ
この札は素札だから、取っても点数にならない。
This card is a worthless card, so even if you take it, you won't get any points.
noun
card worth only 1 point
In hanafuda, a card that is worth only one point, the lowest value.
See also: 花札
花札では、素札は1点の価値しかない。
In hanafuda, a 素札 is worth only one point.