What are penalty retake rules after Roma penalty drama?

A referee can order a penalty to be retaken for a number of reasons in football - but what are the rules after Roma were awarded two retakes in their Europa League defeat against Lille?

The laws on encroachment from penalty kicks comes from Law 14 of the International Football Association Board's Laws of the Game.

It states that the goalkeeper facing a penalty must "remain on the goal line, facing the kicker, between the goalposts, until the ball is kicked".

The goalkeeper must have at least one part of one foot touching, in line with, or behind, the goalline.

Ifab also states the goalkeeper must not 'unfairly distract the kicker'. This includes delaying the taking of the kick, touching the goalposts, crossbar or goal net.

Other players, excluding the penalty taker and the goalkeeper, must also remain outside of the penalty area, inside the field of play and 10 yards away from the penalty spot until the kick has been taken.

If a goalkeeper or a team-mate is deemed to have encroached and the shot has not entered the goal, the kick is retaken.

But if the goalkeeper or their team-mates have encroached and the shot is scored, a goal is awarded.

If the attacking team encroaches and is deemed to have affected the goalkeeper, the kick is retaken if the ball enters the goal. If it does not, an indirect free-kick is awarded to the defending team.

In the event that a player from both teams is found guilty of encroachment, the penalty is retaken. If the encroachment was not deemed to have affected the goalkeeper, play continues.

Thanks to Brian in East Sussex for the question.

This article is the latest from BBC Sport's Ask Me Anything team.

Ask Me Anything is a service dedicated to answering your questions.

We want to reward your time by telling you things you do not know and reminding you of things you do.

The team will find out everything you need to know and be able to call upon a network of contacts including our experts and pundits.

We will be answering your questions from the heart of the BBC Sport newsroom, and going behind the scenes at some of the world's biggest sporting events.

Our coverage will span the BBC Sport website, app, social media and YouTube accounts, plus BBC TV and radio.