The 1 Point Play
 

I thought of the possability of a blocked extra point. The defending team would then return it a majority of the field only to perform a drop-kick (a la Doug Flutie). Is this legal, and if so would it result in the only way to score a single point?

Canadian Scoring
 

1 point can be earned via:

• a coverted touchdown by means of a field goal
• a rouge

A rouge is scored when a kicked-from-scrimmage ball enters an opponents end zone and the ball goes dead in that end zone, in the non-kicking team's possession.

the ball is dead after a blocked extra point. defense can't score.

In NCAA, the defense can score on a try, but can't do so by drop kick. Any kick must be made by Team A before a change of possession, or it is an illegal kick.

If there is a play that would result in a 2 point safety during a normal play (not an extra point play) and it happens on an extra point play, then it scores 1 point. Example- Defense intercepts a pass (offense is going for 2) at teir 1. The guy stats running wide to get around the tacklers. He ends up circling into his own end zone and is tackled there. safety 1 point for the team that attempted the extra point.

by what set of rules does this occur? NF or NCAA?

In what TXMike described, NCAA rules... in NF the ball is dead when B intercepts. However, there is a rule provision giving A 1 point for what would be a safety on B.
It happens when B provides new force (they cant actually gain possession) on a ball going into and out of their own endzone.

one way for A to get one point other than a kick.
A fumbles before crossing the line, and the loose ball goes into the end-zone where B touches it and forces it out of the end-zone
Only A can score; B cannot score on any attempted try (federation)
B touches the ball, and it becomes dead.

The 1 point safety (Tex A&M did this last year) for A doesn't answer the OP's question, as it is exactly the same as a regular XP - 1 point for the offense.

I think the OP was asking how a team could have just 1 point - total.

The same rule, however, gives the only option. A scores, B blocks XP, and A ends with the ball in their OWN EZ (long run by B plus a fumble, with A running the ball into their own EZ, for example). B would score 1 point on such a play, and the score would be 6-1.

In your example, A does not score any points since it was A's force that caused the ball to be in the end zone. Who forced it to go out of the end zone is of no consequence.

Also, you say if B touches the ball it is dead. That is false. B possessing the ball causes it to be dead.

Here is how A can score one point on a non-kick try. A fumbles the ball. While it is grounded and nearly at rest, B muffs the ball into the end zone and falls on it.

A must fumble the ball before he crossing into the end-zone , otherwise it's two points because the pay is over. Whistle and signal
The ball, loose and live in the end-zone must be put out of the end-zone by B. If B falls on a loose ball in the end-zone, the play is over. Why would you award a point to a team that fumbled the ball? The bat by B (new force) through the end-line forced the ball out of play and didn't allow A an opportunity to recover.

In my example, A fumbled the ball before crossing into the end-zone. B then provides a new force that causes the ball to be in the end-zone. If the ball subsequently becomes dead in the end-zone either by B possessing it or either team muffing it out of the end-zone, A is awarded a safety. Because it is a try, A gets only one point instead of two.

REPLY: booker...I think you're still missing an important distinction: FORCE is the energy that puts the ball from the FIELD OF PLAY across a GOAL LINE. It occurs as a result of a pass, kick, fumble, bat, or muff. Once the ball is in the END ZONE, force cannot be added to the loose ball or changed. Your statement that B's bat of a loose ball in the end zone across the end line is a new force is not correct. The force would still be attributed to whichever team put the ball from the field of play into the end zone. In your play where B bats the ball out of the end zone, we will have a flag for an illegal bat, but there's no change in force because of the bat.

You're right about the bat, but once the ball comes to a rest or partially is at rest, a new force can take the ball out of the end-zone.
I'm writing about federation, not college, NFL, or Canadian fb.
If A fumbles before it crosses into the end-zone, and the ball comes to a rest or partially is at rest and a B player (illegal) bats or (illgal) kicks the ball across the end-line it is regarded as a safety against B, and if A accepts the penalty, A is awarded one point.
It doesn't happen that often, but it does happen.

REPLY: I think that maybe we were just talking past each other. As long as B's bat/kick occurs on the loose ball in the field of play (outside the end zone) then I agree completely. In fact, even if B legally muffed the at rest ball into B's end zone and across the end line, it would still be a safety.

When I first read your play, I thought you were saying that A's fumble rolled into B's end zone, came to rest, and then B batted it from there across the end line. This would not be a safety. Agreed?