“It’s time to ditch Skype and Teamspeak. Discord is the only free and secure all-in-one voice+text app designed for gamers that works on your desktop and phone.”
All-in-one voice and text chat for gamers that’s free, secure, and works on both your desktop and phone. Stop paying for TeamSpeak servers and hassling with Skype. Simplify your life.
— Discord (@discordapp) July 29, 2016
Discord is always completely free to use with no gotchas. This means you can make as many servers as you want with no slot limitations.