Calling a gambler a "kubyustus": Kiddushin 11a; Bechorot 5a [see Tosafot, and see Tosafot Ketuvot 58a קוביוסטוס]
Whether the problem with gambling is that the parties don't accept that they will have to give over their funds, since they don't know whether they will win or lose: Eruvin 82a
Cases of Gambling
Dividing portions unevenly, among people who are not part of a unified group: Shabbat 149b
