What is the WWE Wild Card rule?

On the 6th May, 2019 episode of WWE RAW, which was kicked off by Vince McMahon, the WWE Chairman suggested a "Wild Card rule" in the WWE after Roman Reigns had announced on social media earlier this week that he has unfinished business on RAW that he has to finish.

Reigns interrupted Mr. McMahon's speech, followed by former WWE Champion Daniel Bryan, then by current WWE Champion Kofi Kingston, and finally by RAW Superstar Drew McIntyre. Reigns, Bryan, and Kingston are all a part of SmackDown Live, which led to Vince McMahon announcing the Wild Card rule.

What is the WWE Wild Card Rule?

The WWE Wild Card rule will allow Superstars from RAW or SmackDown Live to move between brands "one-night-only appearances". The number of Superstars that can appear from one brand to the other was capped at 3 by Vince McMahon, which was later changed to four after Lars Sullivan made a special visit to the WWE Chairman.

Following RAW, WWE explained more about the Wild Card rule (Read more about it here on WWE.com):

The latest wrinkle in the ongoing Superstar Shake-up emerged this Monday on Raw when Mr. McMahon announced a new “Wild Card Rule” in which a limited number of Superstars from Raw or SmackDown would be invited to cross brand lines for one-night-only appearances, with unauthorized jumps to be penalized by fines or even potential firing.

Apart from Reigns, Bryan, and Kingston, Elias was another SmackDown Live Superstar who appeared on RAW this week, attacking Roman Reigns along with Drew McIntyre and Shane McMahon, while Lars Sullivan brutalized No Way Jose and his conga line.

We've already witnessed one match where the Wild Card rule has been used, in the main event of RAW, where Kofi Kingston successfully defended his WWE Championship against the returning Daniel Bryan.

But WWE has said that the Wild Card rule does not mean that the Brand Split will go away anytime soon.

We will see more of the Wild Card rule on tomorrow's SmackDown Live show, where AJ Styles promised that he will bring some "friends" from SmackDown Live to RAW.