Wasteland 3

You need to get one kill with any weapon that deals energy damage. You can tell which type of weapon it is based on the color of the numbers next to damage while in your inventory. Use any weapon with purple numbers.

White numbers- regular damage.
Yellow numbers- explosive damage.
Orange numbers- fire damage. (Fire it Up achievement)
Blue numbers- ice damage. (Cold Reception achievement)
Purple numbers- energy damage. (This achievement)