There are many different skills required to succeed in football, from quick feet to upper body strength. The skills that a player must have are largely dependent on what position he plays. Also, as a player gets to higher levels he must be stronger and have better technique, as there is little room for error.
Every position on a football team must be strong. Linemen have to be big and strong to push through the opposing linemen. Other blockers such as tight ends also must be strong enough to hold off opposing players. Wide receivers and running backs have to have strength to avoid getting tackled and stay on their feet. Quarterbacks must have strong arms to throw the ball far and fast, and kickers must have strong legs and feet to kick the ball far. Other positions like pass rushers, safeties, and cornerbacks must be strong enough to tackle players with the ball.
Even obscure players like long snappers must be strong enough to propel the ball a long distance. After they snap the ball, they also have to hold off the defensive special teams players trying to rush the kicker.
The only player who might not have to be strong is the holder, but this is usually a player who also plays another position.
Much like strength, speed is a fairly universal skill in football. With the exception of linemen, almost every player must be quick on their feet. Football is a fast sport that involves constant running and shuffling, and even the players who aren't sprinting must have coordinated and quick feet.
Most of the players thought of as "skill players" must have hand-eye coordination. Players such as wide receivers, cornerbacks, and linebackers must have good hands and hand-eye coordination to catch, swat, or intercept passes.
Players also must have coordinated feet and have good balance.
Toughness is fairly similar to strength, but there's a definite distinction. Most players will get blocked or tackled at some point in football. The ability to get back up on your feet is just as important as the ability to knock down someone else.
Linemen clash on every play and have to have serious durability. Running backs take a hit every time they touch the ball, as do many wide receivers.
Like most major sports, football players must be able to focus even during the most stressful situations. A game can come down to one play or one drive, and if the players don't have enough poise they could choke.
A kicker is one position which comes to mind for poise. Many kickers describe their job as a mental battle, much like a golfer. Hitting a game-winning field goal requires the kicker to push through nerves and pressure.
Quarterbacks and middle linebackers must show tremendous poise too. These positions lead their respective groups of offense or defense. If they appear nervous or unfocused, their entire unit will slack.
Many players must also have great endurance. Wide receivers may run long routes on every play of a drive, requiring them to be in great aerobic shape.
In addition to being in good aerobic shape, players must have strength endurance. A quarterback has to be able to deliver a long pass just as well in the last few minutes of the game as he does in the first stages.
All the above skills are important, but they're useless without game sense. Game sense, or football IQ, is one's ability to make intelligent decisions and reads on the field.
From calling audibles and picking holes in the defense to memorizing the playbook, football players must be a lot more intelligent than many people expect. Football is a complex and intricate sport, and it can all come down to one decision.