From the INFC Rulebook:
Section 19
Rules Governing Overtime (Tiebreaker)
Article 1: Overtime (Tiebreaker for INFC Play Off Games)
a. National Federation High School Rules (Oklahoma High
School Rules) will apply.
Article 2: Overtime (Tiebreaker for INFC Regular Season Games)
a. After the coin toss options, play will start at the defensive team’s 25-yard line.
b. Each team will have one series of downs, 1st and goal, starting at the 25-yard line.
c. Teams cannot make a 1st down or be awarded an automatic 1st down.
d. If a defensive team penalty is accepted, the down will be replayed.
e. If an offensive team penalty is accepted, the down will be replayed unless the penalty carries a loss of down.
f. Whichever team has the highest score or the most penetration distance after 4 downs and maintains possession for all 4 downs, wins the game.
g. If both teams have lost yardage after 4 downs, or have lost possession, or have the same score or penetration, the overtime will be replayed.
h. Defensive pass interference carries a 15-yard penalty if accepted plus the down is replayed.
i. The offense must maintain possession. If the defense gains possession of the ball during play, the ball becomes dead and the team in original possession will be recorded with zero yards gained.
j. One point will be awarded for the score in an OT victory.