The concept is good, but executing it would be hard. Most of the times CT's have a hard time keeping all T's in check in the first place, especially late at night when new CT's usually try to hop to guards. Also, if every single T can roll the dice and there are 30+ T's on, and like 5 get ST for one game, how are the CT's going to keep that in order? (Unless you meant this is kind of like bomb, where every 1/10 T's get a chance to roll the dice) It seems kind of all over the place at the moment, but seems like it can be polished further. -1 for now, but has potential!
I had a suggestion and brought it up in the server today of kinda an opposite direction with "dice"
I had a suggestion that the Warden should have a !dice command, where if you add a number after it, it rolls a dice in chat between 1 and the number you put after !dice. For example, "!dice 10" would roll a number in chat from 1 - 10.
This could make for a more variety of random games, like choose a number, you can assign T's numbers 1 - 5 and roll the dice, that numbered T dies, assign markers numbers and tell everyone to pick a marker, etc. All luck based. You can get pretty creative with this too!