Eligible Receiver – An eligible receiver is a player who is legally allowed to catch a forward pass. Only eligible receivers may legally advance past the neutral zone when a forward pass touches or passes through it. In the event that a non-eligible receiver catches a forward pass, the team is penalized for illegal touching. In this case, the play is considered an incomplete pass, or a lost down if the ball has been downed behind the line. When an ineligible receiver advances beyond the neutral zone, the team is assessed a foul for ‘ineligible receiver downfield, which results in yardage loss. Both the NFL and the NCAA play some variation of this rule. In the NFL, any defensive player is an eligible receiver. However, the only eligible offensive receivers are the two players at the ends of the line of scrimmage. The quarterback is generally not an eligible receiver, although there are some rare circumstances where he can be.

Encroachment – Encroachment is an illegal procedure in which a defender crosses the line of scrimmage (into the neutral zone)prior to the ball’s being snapped, and makes contact with an opposing player. The offending team incurs a five yard penalty.The neutral zone is the space (the length of the football) that separates the offensive and defensive teams prior to a play. Only one player is able to legally enter the neutral zone, and that is the center, who snaps the ball to the quarterback to start a play.The foul of encroachment is incurred when the offending defensive player’s contact with an offensive player causes him to have to move out of his stance, or jump. Encroachment is a type of offsides penalty, but differs in that it involves contact with another player. The head linesman is the official who is primarily responsible for watching and making calls of offsides or encroachment

End – In football, an end is a player who lines up at either end of the line of scrimmage, in preparation for a play. Football rules require legal offensive formation to consist of seven players on the line of scrimmage. A tight end is an end player that lines up close in to the offensive line. In contrast, a split end is a player who lines up some distance from the offensive line. The generic term wide receiver is sometimes used in reference to both split ends and flankers. Flankers are players who line up in a split position but do so behind the line of scrimmage. Defensive end is a very commonly used defensive position. NFL and NCAA rules do not dictate defense formations. For this reason, players in the position of defensive end often share their roles with other positions in different defensive schemes.

End Line – The end line is a boundary line connecting the two parallel sidelines. Together, the side lines and the end line define the two end zones, which are located on opposite sides of the field. The end zone has white lines to indicate beginning and end points and orange pylons situated at each corner to serve as visual aids in establishing boundaries. The end line is 6 feet wide, and with the sidelines, makes the rectangular shape of a regulation football field. The end of the end line is also marked by two orange pylons. The end zones are two areas, 10 yards wide each, at the opposite ends of the field on the inside of the end line. The end zone that is behind a team is that team’s end zone, while the end zone that the team faces belongs to the opposing team.

End Zone – The end zone is a 10-yard-wide section situated at either end of the field. Carrying the ball into the end zone results in a touchdown. The end zone that is behind a team is that team’s end zone, while the end zone the team faces belongs to the opposing team. The end line is a six foot long boundary marker that connects the two parallel sidelines to define the rectangular playing field. Orange pylons are situated at each corner of the end zone to serve as visual aids for players, fans and game officials. The goal posts, poles that stand 10 feet high, are centered at the back of each end zone. While a regulation American football end zone measures 10 yards (long) by 53.5 yards wide, Canadian football end zones are larger. Because Canadian football is played on a larger field, the enA team is assessed a penalty for excessive time outs. This penalty is called when a team requests a time out after the allotted three have already been taken. Because calling a time out stops the clock, which usually runs between the plays, it extends the time that a team has to score. Thus, the wise use of timeouts can greatly affect the outcome of a game. Timeouts may be called by players or the team’s coach. Both the NFL and the NCAA allow each team three timeouts per half. When a team successfully calls a timeout after it has already used its allotted number, the team is given a five yard penalty and the clock is re-started to resume play. If an excessive timeout is called, and the officials do not recognize it, they simply signal the teams to continue playing and there is no penalty incurred.

Extra Point –In football, the chance to kick the ball through the uprights after scoring a touch down for an additional point is called an extra point. The extra point is alternatively referred to by other names, such as: conversion, try, extra point, point after touchdown, point-after try or PAT. If the kick successfully goes through the uprights, the team receives one additional point for that touchdown. A team may instead choose to try a two point conversion by running or passing from the scrimmage. NFL rules require that the scrimmage for point after a touchdown occurs at the two yard line, although in high school and college football, it is the three yard line. During an extra point attempt, the game clock is stopped. If a game runs into sudden death overtime, an extra point attempt is not required if the winning score is a touchdown.