>surface
/gen good
group(type=structure,ID=gen_good;type=block,ID=lucky:lucky_block_awesome,posy=#bPosY+1,tileEntity=(Luck=75))@chance=600

/gen bad
group(type=structure,ID=emerald_ruins_natural;type=block,ID=lucky:lucky_block_awesome,NBTTag=(Luck=-75))@chance=500