These are the effects of the Devil's Dice, as I have tested.
You are warned, DO NOT SCROLL DOWN IF YOU DON'T WANT THEM RUINED FOR YOU!
1 Set Dice -
1: You do less damage.
2: You move slower.
3: You're invisible, but very weak against fire.
4: Faster Speed.
5: Immunity to Fire
6: Free power ups. (1~2 spawn, to what I've seen. Mostly runes. I one time got armor.)
2 Set Dice -
3: Monster damage is cut in half. Speed is halved.
4(Doubles): Fire damage converted to mana.
5: You're fast, and invisible, but take more damage and deal less.
6: Gives the effect of infared goggles. Can't be stacked with goggles.
6(Double Three): You're nearly invincible, but blind!
7: High Jump
8: Immunity to ice, and physical (Melee) damage.
9: Summons one or two assistants to aid you (Marines). The red one has a grenade launcher, and a riot gun.. The gray one has a nail gun, and a standard pistol. They don't walk around until hit. (Tested with Colts.) They drop their weapons and ammo when they die.
10: Infinite Ammunition, at the cost of reduced damage.
11: More free power ups. I was given a mana cup, and a rune of regeneration. More testing gave infared goggles, and bracers.
12 (Double Sixes): Time Freezes, The World! (This lasts awhile. 10 seconds at best.)
As you can see, it still needs ALOT of work.