<Li> The Canadian Football League prohibits the use of the helmet to butt, ram, or spear an opponent . Players are penalized for what is not deemed to be an' acceptable' football play . </Li> <Ul> <Li> In the NCAA, helmet - to - helmet collisions have been banned for years, but they were illegal only when intentional . In 2005, the NCAA took the word "intentional" out of the rules in hopes of reducing these incidents even further . Beginning with the 2013 season, players who are flagged for such hits are automatically ejected from the game in addition to a 15 - yard penalty, under the new "targeting" rule, subject to a replay review . If the ejection occurred in the second half or in overtime, the player must also sit out the first half of his team's next scheduled game . This rule was revised in 2014 to overturn the yardage penalty in addition to the ejection if the player's hit is not flagrant . The rule was again revised in 2016 to allow replay officials to call penalties if they were missed by on - field officials and overturn incorrect penalties . The NCAA is currently proposing to modify the policy again to allow players to remain in the game if there is insufficient evidence for replay officials to confirm or overturn a call, but the 15 yard penalty would still be enforced . </Li> </Ul> <Li> In the NCAA, helmet - to - helmet collisions have been banned for years, but they were illegal only when intentional . In 2005, the NCAA took the word "intentional" out of the rules in hopes of reducing these incidents even further . Beginning with the 2013 season, players who are flagged for such hits are automatically ejected from the game in addition to a 15 - yard penalty, under the new "targeting" rule, subject to a replay review . If the ejection occurred in the second half or in overtime, the player must also sit out the first half of his team's next scheduled game . This rule was revised in 2014 to overturn the yardage penalty in addition to the ejection if the player's hit is not flagrant . The rule was again revised in 2016 to allow replay officials to call penalties if they were missed by on - field officials and overturn incorrect penalties . The NCAA is currently proposing to modify the policy again to allow players to remain in the game if there is insufficient evidence for replay officials to confirm or overturn a call, but the 15 yard penalty would still be enforced . </Li> <Ul> <Li> Former Carolina Panthers running back Eric Shelton sued the NFL in 2010, alleging that a helmet - to - helmet collision caused him a spinal cord injury that left him paralyzed, and he was not appropriately compensated for his injuries . </Li> </Ul>

When did helmet to helmet hits become illegal
find me the text answering this question