There's no macro ability to highlight or define critical ranges. One suggestion is to have you macro work like this: Longsword attack [[1d20+5]] Critical: [[19+5]] The second line is there to basically show what the roll will look like if it is a crit. So if your range is 19, then that means 19 plus whatever your bonus is, will be the displayed value on a critical roll. If the two match, it's a crit.