noun
Formal or literary term for dice. In everyday speech, サイコロ is much more common.
See also: サイコロ
賽を振って、出た目で勝負を決める。
Roll the dice and decide the match by the number that comes up.
このゲームでは二つの賽を使います。
This game uses two dice.
Rarely used kanji form for 'dice'.
The common, everyday word for 'dice'. 賽 is its formal or literary equivalent.
The kanji 賽 is used for its meaning related to dice. The reading さい is a Sino-Japanese reading. The word is a formal/literary term, while the more common サイコロ is of uncertain origin, possibly from 采 (さい) + 子 (ころ).