Academy teams from England, France, Germany and Belgium took part in the Premier League Christmas Truce Tournament, in Ypres, Belgium.
While the event seeks to educate the Under-12s about the First World War, the action on the pitch is also important, as they face unfamiliar styles of play and tactics.
Crystal Palace's Richard, Rory and Joshua, and Abdul from West Ham United explain what they learnt from the tournament.
The opening day of competition…
Rory: Coming up against teams we haven't played before, like Anderlecht and Schalke, gave us an opportunity to play a different way. You can also pick things up from what they are doing.
Joshua: Even though we lost some matches, we all improved and got better. Next time we know what to do.
See: 'It hit me how so many people lost their lives'
The main thing you learnt from the matches…
Richard: You are going to have ups and downs in football, and even when you are having the down times, you have to keep your head high.
Rory: To enjoy it a bit more because I am so focused on the fixtures, sometimes I don't take the fun from it. You have to enjoy the experience of playing against teams from different countries in a tournament like this. It is a big opportunity.
Abdul: If you become a professional footballer, you will be coming up against such teams. This is a good experience for the future. It's also a good thing to meet the other boys as it shows that football can link anyone together.
On West Ham qualifying for the semi-finals…
Abdul: I feel proud of our journey. Playing the top teams in Europe and getting to the last four is a great achievement. When we got back to the hotel, we talked about the need to stay focused.
On Crystal Palace beating Club Brugge on the final day…
Richard: We had just lost to Paris Saint-Germain and a lot of the boys were in a bad mood. To come back from that to win showed a lot of spirit.
When the final whistle went in the Brugge game, we felt relieved. We did it for the parents because they came all the way to support us and we wanted to give them something.
On West Ham's defeat by Anderlecht in the last four:
Abdul: It was a tough match. We didn't stick to our plan and they did not give us a chance to play the way we wanted to. It was disappointing but it was a good learning experience for us. They are a top side to play against.
But West Ham beat Blackburn to claim third…
Abdul: [Beating Blackburn] means we are a good side and a hard-working team. It's one of the best tournaments I have ever played in. Coming third is a positive that will help us in the future.
One thing you will take from the tournament….
Rory: You take more from losing than winning. If you don't play well you learn more and you make sure you do it next time.
Richard: That things might not always go your way but you should keep on trying until it does.
Joshua: Football is not all about winning, it's about improving too.
A memory from the weekend…
Richard: The gift exchange, because we got to meet lots of new people who we plan to stay in touch with.
Rory: The education day and the match against Schalke when we came from behind to go 2-1 up but they scored an equaliser with the final kick of the match. It has never really happened for me before and it will always stick in my mind.
Abdul: From the football side, the result we got but the main thing is the educational side, learning about the history and what happened in World War One. I will pass it on to my friends.