Generates a random number between 0 and the given maximum.
- The maximum of the range.
rnd() function returns a random number in a range. The result is between 0 and the given maximum, inclusive of 0 but exclusive of the maximum.
The random number includes a fractional part. To get a random integer, use
The random number generator is initialized with an unpredictable seed value when Pico-8 starts. You can reinitialize the generator with an explicit seed (such as to test random behaviors with a known sequence) using srand().
Working with ranges Edit
To select a random number between a minimum and a maximum, call
rnd() with the size of the range, then add the minimum:
x = rnd(32) + 64 -- a random number between 64 and 96 scale = rnd(20) - 10 -- a random number between -10 and 10 die = flr(rnd(6)) + 1 -- a random integer between 1 and 6
To select a random fraction with a fixed number of decimal digits, use
flr(rnd(...)) with the range times the precision, then divide by the precision:
earnings = flr(rnd(50 * 100)) / 100 -- between 0.00 and 50.00
Alternate ranges Edit
rnd() called with a negative value for
max returns a random value in the range of all numbers, from -32768.0 to 32767.0.
rnd() called without a
max value (
nil) returns a random value in the range from 0.0 to 1.0.
rnd() appears to accept a
max value outside the Pico-8 number range of -32768 to 32767 if the argument is a number literal or literal expression (such as
rnd(50000)). The result may overflow the range and be negative.
print(rnd(20)) -- for example, 3.837 print(flr(rnd(20))) -- for example, 17