Press ENTER each time you want to throw the dice. To use % RND instead, change line 40 to read:

40 PRINT %1+ RND 6;" ";

and to use RND () you need to write line 40 as:

40 PRINT 1+ RND (6);" ";

Aren't the latter two more readable?

The RANDOMIZE statement, is used to make RND and % RND start off at a definite place in its sequence of numbers, as you can see with this program:

10 RANDOMIZE 1
20 FOR n=1 TO 5: PRINT % RND
   100,: NEXT n
30 PRINT: GO TO 10

After each execution of RANDOMIZE 1, the % RND sequence starts off again with 97 and if you use RND instead of % RND 100, you'll get 0.0022735596. You can use other numbers between 1 and 65535 in the RANDOMIZE statement to start the RND sequence off at different places.

If you had a program with RND, RND() or %RND in it and it also had some mistakes that you had not found, then it would help to use RANDOMIZE like this so that the program behaved the same way each time you ran it.

RANDOMIZE on its own (and RANDOMIZE 0 has the same effect) is different, because it really does randomise RND, RND() and % RND – you can see this in the next program:

10 RANDOMIZE
20 PRINT % RND 65535: GO TO 10

The sequence you get here is not very random, because RANDOMIZE uses the time since the computer was switched on. Since this has gone up by the same amount each time RANDOMIZE is executed, the next % RND does more or less the same. You would get better randomness by replacing GO TO 10 by GO TO 20. Here is a program to toss coins and count the numbers of heads and tails.

10 heads,tails=0
20 coin=% RND 2
30 ON coin: heads+=1:tails+=1
40 PRINT heads;",";tails,
50 IF tails<>0 THEN PRINT
   heads/tails;
60 PRINT: GO TO 20

The ratio of heads to tails should become approximately 1 if you go on long enough, because in the long run you expect approximately equal numbers of heads and tails.

Note that RANDOMIZE can also be written in short as RAND and it will expand to RANDOMIZE!