Print a short phrase on a critical hit?

My character has recently found a Vorpal Sword. I figure it would only be appropriate that when I make a critical hit with it not only rolls the extra damage, but also prints out " snicker snack " as part of the roll output. How would I do this? Thanks!

Are you using the DnD 5e by Roll20 (2014) sheet? If you are, you can use row injection to put a custom critical damage roll on your attacks - here's how you do it: 1. Get a critical hit with a weapon - just set yourself to have advantage, enter /talktomyself, and keep swinging until you see the green. 2. Roll the critical damage. 3. In the chat input field, press up - this will bring up the generated call for the damage roll. Copy this. 4. In the Attributes & Abilities section of the sheet, create an ability - name it what you like, "Vorpal_crit" for instance. Write your text in that ability, line break, and then paste the call you copied in previous step. Save the ability. "Snicker Snack!" the pasted ability call 5. Go back to the weapon attack on the character sheet - open it up, and in the description field of the attack, enter }} {{rnamec=[Damage](~character_name|Vorpal_crit) (use whatever you named the ability you saved). You can also change the button label from "Damage" to "Snicker Snack" if you'd like.

Brandon said: My character has recently found a Vorpal Sword. I figure it would only be appropriate that when I make a critical hit with it not only rolls the extra damage, but also prints out " snicker snack " as part of the roll output. How would I do this? Thanks! Tuo mentions one way to do this, but I must add: in general, you can only do this with a script if you are Pro user (or a rollable table if you aren't, which can only be done in certain cases). The standard roll20 dice rolls cannot do this. If you need another way than that suggested by Tuo, look into solutions like ScriptCards.

Both my GM and I are Pro users.  Thanks for the info!