This year's schedule includes the most teams in the event's history, 54 (28 girls, 26 boys). Games will begin at 9 a.m. and run through about 6 p.m. on seven fields around Radnor's campus.
The marquee matchup will feature Conestoga (11-2) and Haverford School (14-1), two of the nation's top boys' teams, at 1:30 p.m. Conestoga, ranked seventh in the nation by ESPNHS, is the defending PIAA champion. No. 3 Haverford beat the Pioneers, 11-6, at last year's festival.
Both teams boast a plethora of Division I prospects, including the Fords' Will McNamara, a midfielder bound for Virginia and the country's No. 2 recruit in the class of 2012, according to ESPN.
Conestoga coach Brian Samson is Katie's brother.
"We're really proud of the event and what it's become," he said. "It's exciting for me to be part of it as a coach, but also extended support for my sister."
He added: "We approach it likes it's any other game. It has a lot of significance because of the opponent. It would be a big game regardless of where it took place. . . . But we try to think of it as something bigger than just our team."
Among girls' games, defending PIAA champ and sixth-ranked Garnet Valley will play No. 18 St. Stephen's & St. Agnes (Alexandria, Va.) at 2:15.
Attendance is expected to be around 10,000, with all proceeds going to spinal-cord injury research and patient care. Admission is $8, free for children three years old and younger.
In addition to the lacrosse, the festival will feature a carnival-like atmosphere, equipped with two fan zones, "Katie's Kiddie Korner" with rides, face painting and raffles, and games of wheelchair rugby - Katie Samson's new sport - and basketball.
It is the largest single-day lacrosse festival in the nation, according to the event's Facebook page. To donate or to learn more, visit www.katiesamsonlaxfest.com.
All games at Radnor High School.
Germantown Academy vs. Emmaus, 9:30 a.m.
Cardinal O'Hara vs. West Chester Rustin. 9:30
Hatboro-Horsham vs. Archbishop Wood, 9:30
La Salle vs. Downingtown East, 11:30
Archbishop Carroll vs. Harriton, 11:30
St. Augustine Prep vs. Garnet Valley, 11:30
Haverford School vs. Conestoga, 1:30 p.m.
Shipley vs. Haverford High, 1:30
Brunswick School vs. Downingtown West, 1:30
Malvern Prep vs. Lawrenceville, 3:30
Hill School vs. Penn Charter, 3:30
Episcopal Academy vs. Springfield (D), 3:30
Radnor vs. St. Joseph's Prep, 4
Notre Dame vs. Great Valley, 9 a.m.
Shipley vs. Penncrest, 9
Villa Maria vs. West Chester Henderson, 9
Radnor vs. Episcopal Academy, 10:45
Friends' Central vs. Upper Dublin, 10:45
Baldwin vs. Boyertown, 10:45
Mount St. Joseph vs. Conestoga, 12:30 p.m.
Springside vs. Methacton, 12:30
Penn Charter vs. Unionville, 12:30
St. Stephen's & St. Agnes vs. Garnet Valley, 2:15
Hill School vs. Downingtown East, 2:15
Archbishop Carroll vs. Harriton, 2:15
Agnes Irwin vs. Haverford High, 4
Germantown Academy vs. Abington, 4
Contact Evan Burgos at email@example.com.