This is a really cool method to use for your main lift.
Singles
Warm up until you are at about 50% of your 1RM. Now start doing singles, adding 10 kg per set until you are at a weight where you think that you could not have done more than 3 reps. Go higher only when you feel really awesome.
Throw the die
Now you take out a die, throw it, and let it decide what you do next.
Your first set after the throw you will try to hit a new PR weight for the number of reps that the die shows. Since we have already done singles we want to do at least 3 reps. Because of this we let 1 mean 10 reps, and 2 mean 8 reps. After you have done the PR attempt. you will keep the weight the same, and try to accumulate the number on the die times 4 in total reps.
What to do for each possible outcome is shown below:
6 -> You go for a 6 rep personal best, then try to accumulate 24 reps with the same weight.
5 -> You go for a 5 rep personal best, then try to accumulate 20 reps with the same weight.
4 -> You go for a 4 rep personal best, then try to accumulate 16 reps with the same weight.
3 -> You go for a 3 rep personal best, then try to accumulate 12 reps with the same weight.
2 -> You go for an 8 rep personal best, then try to accumulate 32 reps with the same weight.
1 -> You go for a 10 rep personal best, then try to accumulate 40 reps with the same weight.
Example
To clarify this a bit, we take the example of a lifter that can do a max bench press of 140 kg:
70x1, 80x1, 90x1, 100x1, 110x1, 120x1
He throws the dice, and it shows a 4.
His best ever at 4 reps is 110 kg.
He puts 115 kg on the bar and does 4 reps.
4x4=16 so he is supposed to accumulate 16 reps total with 115 kg.
He does the following sets.
115x3, 115x3, 115x2, 115x2, 115x1, 115x1. And he is done.