First of hello every one, its my first day with PICO 8.

My problem is that i try to select a sprite randomly but only between two sprite ids/variables but i cant seem to make it function. Im maybe just a bit too tired but would love some help thanks.

function _init()

sidetopl = rnd(9) 
sidetopr = rnd(3) 
sidelowl = rnd(7) 
sidelowr = rnd(5) 	

end

function _update()

if (sidetopl == 8 or 9) then
else 
  sidetopl = rnd(9)
end
if (sidetopr == 2 or 3) then
else 
  sidetopr = rnd(4)
end
if (sidelowl == 6 or 7) then
else 
  sidelowl = rnd(7)
end
if (sidelowr == 4 or 5) then
else 
  sidelowr = rnd(5)
end

end

You have to declare your variable with your conditions.

if sidetop==8 or sidetop==9 then
   ...do something...
end

And you don't need to wrap your conditions in parenthesis either. You can save some tokens that way.

But also know that rnd() will return a decimal between 0 and the number you pass. So rnd(9) will never return the number 9. At best it will return something like 8.9999. If you want a whole number, you need to use flr() with your rnd() - that will round it down to the nearest whole number.

sidetop = flr(rnd(9))

The example above will return 0,1,2,3,4,5,6,7 or 8. But never 9.
If you want want...

sidetop = flr(rnd(9))+1

This will return 1,2,3,4,5,6,7,8 or 9...but never 0.

I have some helper functions I use for getting random numbers. Maybe they can help you too.

-- get a random number between min and max
function random(min,max)
	n=round(rnd(max-min))+min
	return n
end

-- round number to the nearest whole
function round(num, idp)
  local mult = 10^(idp or 0)
  return flr(num * mult + 0.5) / mult
end