Question : Does the goal line count as a touchdown?
Answer : It depends.
When an offense is moving to try to score, if the runner reaches the goal line, it is considered a score. (Example: a runner starts at the one yard line and rolls a 1 yard gain. Technically. that brings him to the goal line and that counts as being in the end zone.
BUT – it is not always the case…
When you are talking about a returner (punt return, kick return, interception return) if the runner carries the ball to the goal line, it is not considered the end zone. The key is the runners goal. That is achieved.
In real life, if any part of the ball is in the field of play, it is considered being out of the end zone. Since all our play results are considered to be at the exact middle of the yard line indicated, a return to the goal line is in the field of play. Real-life rules state that the ball be placed at the 1/2 yard line with a first down. Since we do not do 1/2 yard lines, we would place the ball at the 1.
The ruling officially is that the yard line a player is attempting to reach is considered gained when stopped exactly at the point. It works the same way with a fourth and 1. If you gain one yard, it is considered gained.
Optional House Rule (not official): Bring out the chains for a measurement. To do so, the coach attempting to reach the yard line rolls a d20. 1-10 they gain the yard, 11-20 they fail. (The ball is still marked on that yard line in the case of a turnover.)