The XFL's official rulebook includes more than two dozen changes to the conventional approach of pro football, according to league officials who are rolling out the specifics this week.

Most of the tweaks, such as a running game clock and a three-tiered extra point, are focused on accelerating the pace of games and elevating interest in traditionally tedious plays.

"What we did is listen to fans," XFL commissioner Oliver Luck said. "And what they told us is that they love this game, but they would like it at a little more of a faster pace and with a little more excitement. They thought there is too much idle time. We tried to listen to what they didn't want, also. They didn't want gimmicks or things that were inauthentic. They also didn't want to be complicit when it comes to player safety. So what we wanted to do is take a great game and make it a little better."

The XFL's eight teams opened training camp this week and will kick off their 10-week regular season Feb. 8. Most of the on-the-field product will look familiar to fans, but a two-year project to innovate some aspects of the game led to a number of significant changes. They include: