Safest? No gambling game are safe to play. All have risks. If you are talking about a "safe place to play" then try crypto-games. You won't be disspointed.
i agree on dice but i dont agree on lotto . im talkin about lotto the offline one here on our place but maybe the mechanics of other lotto games are different on other country . i know all can learn it when we give a time to read and practice it but if you are a newbie i cant say that its not really user friendly . im not sure about the lotto that we find online but i have tested lotto on freebit where you can only buy tickets and your automatically joined and entitle to win prize if you got lucky . this one is easy