Basic and such.

3. Offensive Line:
The big lumps whose job is to
protect the quarter-back on
passing plays and create holes
in the defensive line during
running plays.

4. The guy in the middle is called the Centre
(C) and he's the one who throws the ball
through his legs to the quarter-back.
Outside of him are the Guards (G) and
outside of them are the Tackles (T) .
Once the ball is snapped it is rare that these
players handle the ball.

5. QB - Quarterback:
He controls the game, calling
plays and throwing the
passes to his team-mates.

6. WR – Wide Receivers:
He’s the fastest players on the team.
When the quarterback tries to pass the
ball over longer distances, he will be
looking to pick out his wide receivers.

7. RB - Running Back:
This is the guy you see standing beside or
behind the quarter-back when the ball is
snapped. If the offense opts for a running play
the quarter-back will hand the running back
the ball and he'll start legging it until he gets
tackled.

8. If there appears to be two running
backs and one of them is a bit fatter
than the other, the fat one will
probably be a Full Back (FB) who is
there to block for the other running
back.

9. TE - Tight Ends:
Big guys with good hands who line up on
the outside of the offensive line. Their
unique skill set means they can be used to
block or to catch the ball on passing plays.
They won't be the quickest players so they'll
generally be used on short passing plays
but their height means they can be picked
out even when covered by the defense.

11. Defensive Line:
Consists of anywhere from three to six
players who line up in front of the offensive
line. Their job is to occupy the offensive line
to allow the linebackers to get to the
quarter-back or stop the running back.
Exact positions can change, but the
defensive line can be made up of Ends (E)
and Tackles (T).

12. Linebackers:
They line up behind the defensive line and
they'll sometimes rush the quarter-back
looking for a sack or defend potential
receivers but their main task is to prevent the
run up the middle. The ones lined up on the
outside are unsurprisingly known as Outside
Linebackers (OL) and the one in the middle
is equally unsurprisingly known as the
Middle Linebacker (ML).

13. Defensive Backs:
You'll also hear these players referred to
as the secondary and consists of
Cornerbacks (CB) and Safeties (S). Their
role is to cover the wide receivers, so they
need to be quick and mobile to follow the
routes. Occasionally they'll rush the
quarter-back on a blitz but this is a risky
tactic which leaves the downfield wide
open.

15. There are group of players for attacking, a
team for defending and a team for kicking
the ball. The kicking and returning units
are called special teams and their job is
either to kick the ball into the oppositions
territory and prevent them from running it
back or to receive the ball and get as far
back down the field as possible.

19. UMPIRE
Primarily
responsible for
spotting the ball
at the beginning
of plays.
REFEREE
Is responsible for
the general
supervision of the
game and has the
final authority on all
rulings.

20. HEAD LINESMAN
Responsible for the
chains used to verify
how many yards a
team has covered
during a play.
LINE JUDGE
Responsible for
time keeping and
helping the
Linesman to set up
the line of
scrimmage.

21. BACK JUDGE
Responsible for
monitoring the
duration of time outs
and half-time.
FIELD JUDGE
Tends to stand
towards the rear of
the field and makes
sure players are
in-bounds.

22. SIDE JUDGE
Also responsible for
ensuring players remain
in-bounds and supervising
play on his side of the field.

24. Clock doesn’t stop.
The referee moves
an arm clockwise in a
full circle in front of
himself to inform the
offensive team that it
has no timeouts, or
that the ball is in play
and that the
timekeeper should
keep the clock
moving.

25. First down.
The referee points
with his right arm at
shoulder height
toward the defensive
team’s goal to indicate
that the offensive
team has gained
enough yardage for a
first down.

26. Fourth down.
The referee raises one
arm above his head
with his hand in a
closed fist to show that
the offense is facing
fourth down.

27. Holding.
The referee signals a
holding penalty by
grabbing one wrist with
the clenched fist of his
other hand and pulling
his arm down in front of
his chest.

28. Illegal forward pass.
The referee puts one
hand waist-high
behind his back to
signal an illegal
forward pass. The
referee then makes
the loss of down
signal.

29. Illegal motion.
The referee
flattens out his
hand and moves
his arm to the side
to show that the
offensive team
made an illegal
motion at the snap
or prior to the
snap of the ball.

30. Illegal push.
The referee uses
his hands in a
pushing movement
with his arms below
his waist to show
that someone on
the offensive team
pushed or illegally
helped a ball carrier.

31. Illegal shift.
The referee uses
both arms and
hands in a
horizontal arc in
front of his body to
signal that the
offense used an
illegal shift prior to
the snap of the
ball.

32. Incomplete pass.
The referee shifts his
arms in a horizontal
fashion in front of his
body to signal that
the pass is
incomplete, a penalty
is declined, a play is
over, or a field goal
or extra point attempt
is no good.

33. Ineligible player
downfield.
The referee places his
right hand on top of his
head or cap to show
that an ineligible
receiver on a pass
play was downfield
early or that an
ineligible member of
the kicking team was
downfield too early.

34. Intentional
grounding.
The referee waves
both his arms in a
diagonal plane
across his body to
signal intentional
grounding of a
forward pass. This
signal is followed by
the loss of down
signal.

35. Juggled pass.
The referee gestures
with his open hands in
an up-and-down
fashion in front of his
body to show that the
pass was juggled
inbounds and caught
out of bounds. This
signal follows the
incomplete pass
signal.

36. Loss of down.
The referee
places both
hands behind his
head to signal a
loss of down.

37. Touchback.
The referee signals
a touchback by
waving his arms
and hands above
his head and then
swinging one arm
out from his side.

38. Touchdown.
The referee extends his
arms straight above his
head to signify that a
touchdown was scored.
He also uses this signal
to tell the offensive team
that it successfully
converted a field goal,
extra point, or two-point
conversion.