And it was all fun and games until he ran into a busy interesection, where the freshman engineering major was struck by a bus that ran a red light, flinging him into the air to the horror of dozens of foam sword-holding students.
Yet Engmann was able to get up on his own before and walk to the sidewalk, where he lay down. He was taken to the hospital and released hours later, with only a sling on his arm, My Fox Austin reported.
In a video of the accident, Engmann is seen running into the street with a sword before the bus slams into him.
The bus driver was placed on paid administrative leave.
On his Facebook page, Engmann wrote that he was "sorest guy on the planet.”
"Not going to the Undie Run," he wrote. "Adreniline = long gone, pain killers = barely helping."
The foam sword fight tradition began years ago at the UT School of Architecture.
Participants often dress up in funny costumes and let out stress brought on by studying for final exams and projects.
Students stand on opposite sides of a crosswalk until someone signals the fight to begin.
On the Facebook event, organizers do warn students to "Make sure the cars have STOPPED before you charge."
The event was halted after Engmann's accident.
"Sorry the event got halted because of me fellow Longhorns!" He wrote apologetically on the event's Facebook wall. "I'll individually try and make it up to you all :) Hook em!!"