I need a simple buff macro for: At 3rd level, a lore warden gains a +2 bonus on all CMB checks and to his CMD. This bonus increases to +4 at 7th level, +6 at 11th level, and +8 at 15th level. It seems pretty simple, +2 for every 4 levels after 3rd. It is the fact it doesn't start at level 1 which is throwing me off. Can anyone help?