create new wariable 'random choose'
and try this: every 5 seconds set 'random choose' and type this: int(random(1,3) roll number between 1 -3
other event:
if 'random choose' is 1 add +1 to speed
if 'random choose' is 2 add +1 to attack
if 'random choose' is 2 add +1 to defense
+
set 'random choose' to ZERO
but when number has been