According to the lawsuit, obtained by TMZ, Mark Schaefer and Adam Rahman say they were shot and severely injured in the February 2022 shooting outside The Nice Guy in L.A. ... and they're blaming Justin, Kodak and the venue.

TMZ broke the story ... three people, including Kodak, were shot outside the party... and Kodak's camp says when he was leaving the venue someone in his crew got jumped by an unidentified assailant, with the rapper throwing himself into the mix to help his pal out before shots rang out.

In the docs, the alleged victims claim Kodak was a major catalyst in the shooting ... they say he was trying to cause harm and escalate the situation and they're laying the blame for the shooting squarely on his shoulders.

What's more, the alleged victims claim security at the venue was lax ... they say the security guards who were hired couldn't handle the job, and the venue, promoters and performers, therefore, bear some responsibility, too.

The alleged victims are going after Kodak, Justin, The Nice Guy, The Hwood Group and Revolve Group, plus the City of Los Angeles, the City of West Hollywood and Los Angeles County for damages ... and they're being repped by Gloria Allred.

Kodak's attorney, Bradford Cohen, tells TMZ ... "I have seen a lot of bad complaints in my day. This is the most poorly drafted complaint I have seen in 26 years. I expect Kodak to be dismissed from this suit fairly quickly."

Cohen continues ... "There is zero specificity in the complaint and Ms. Allred groups the defendants all together instead of making specific allegations against each. It's law school 101. I am embarrassed for Ms. Allred that she actually signed her name to that complaint."