That is very doable... although your (chance == chance) logic seems very flawed... I'm not sure what you were actually attempting to achieve with this?

Looking at the code you have, it seems that you want to modify the multiplier every 30 losses... returning to basebet if you win? and changing HIGH/low every 30 losses...
Hopefully, this code should do what I think it is that you're attempting to do
NOTE: This code is completely untested, use at your own risk. It probably won't even run without editing.chance = 49.5 -- EDIT THIS
bethigh = true
basebet = 0.00000001
nextbet = basebet
multipliers = {1,1.112,1.113,1.115}
losscount = 0
stepcount = 1
maxstep = #multipliers
function dobet()
if (win) then
nextbet = basebet
losscount = 0
stepcount = 1
else
losscount = losscount + 1
if losscount == 30 then
stepcount = stepcount + 1
if stepcount > maxstep then
-- make sure we don't exceed the size of multipliers table
stepcount = maxstep
end
losscount = 0
bethigh = !bethigh
end
nextbet = previousbet * multiplier[stepcount]
end
end
As currently setup, assuming a loooooong losing streak, this should go something like:
Roll 1: HIGH - 0.00000001 - Loss
Roll 2: HIGH - 0.00000001 - Loss
Roll 3: HIGH - 0.00000001 - Loss
...
Roll 30: HIGH - 0.00000001 - Loss
Roll 31: low - 0.00000001112 - Loss
Roll 32: low - 0.00000001236 - Loss
...
Roll 60: low - 0.00000021729 - Loss
Roll 61: HIGH - 0.00000024184 - Loss
Roll 62: HIGH - 0.00000026917 - Loss
...
Roll 90: HIGH - 0.00000539379 - Loss
Roll 91: low - 0.00000601407 - Loss
Roll 92: low - 0.00000670569 - Loss
...