What is paid subscription needed for in Mortal Kombat 11?

Mortal Kombat 11 is being released for Xbox One, Playstation 4, Nintendo Switch, and PC. If you wish to play multiplayer on any of the consoles (PC excluded, usually) you need to pay for their online subscription services in order to play multiplayer games.

You need to have either PS+ or Xbox Live Gold to play the online part of the beta. Paid subscription refers to PS+ or Xbox Live Gold, which are sold separately.

Is a PlayStation Plus or Xbox Live Gold membership required for the beta?

A PlayStation Plus subscription or Xbox Live Gold membership is required to participate in online multiplayer matches during the closed beta. These subscriptions are not required to enjoy the Custom Character Variation System or Towers of Time content.