Game of Thrones was released by HBO, and the first episode aired on April 17, 2011 and it is truly difficult to imagine that it has actually been 15 years since everyone first saw Westeros. To celebrate, HBO has produced a special teaser for the anniversary that will surely send many people back to their Max account to do another rewatch of the series.On April 1, the Game of Thrones social media and HBO accounts released a teaser video for the upcoming event with the hashtag #GOT15. This video highlights all live-action series that have been created, Game of Thrones, and the next immediate series, House of the Dragon and the new series, A Knight of the Seven Kingdoms. As a whole, the video also shows off the wonderful 15-year history that the franchise has provided its viewers with.Through Season 1 of the show, a line which Cersei Lannister said has brought definition to both the show as well as the original title, and has basically told all viewers of what they should expect to see going forward with the series."When you play the game of thrones, you win, or you die".This line is extremely effective as an opening to a teaser because it is so simple, but also one of the greatest lines from television. Along with that, it also brings you back to great dramatic moments from Game of Thrones, where all was in doubt, and you did not know who would die or how events would play out.The teaser also contains a montage of the most interesting events from Game of Thrones, including the Battle of the Bastards and the Red Wedding. These are also displayed in subsequent clips from the spin-off series over other clips, including Ser Duncan the Tall preparing to battle in the spin-off series A Knight of the Seven Kingdoms and Daemon commenting on the dragons from the spin-off series House of the Dragon. All of these clips were presented in a single continuous montage.While this clip is short, it does a good job of showing what has been built over the past 15 years of this franchise and how the franchise continues to progress.What does the Game of Thrones 15th anniversary teaser include, and why does it work?As a promo video, this one serves a completely distinct role in that its objective in this teaser is to notify you of the fact that each of the live-action series belonging to the franchise is set within a shared universe, along with a single story shared by all. The number of seasons that exist within the shared universe is truly amazing.The House of the Dragon series began airing in 2022 and tells the story of a Targaryen civil war, which is commonly referred to as The Dance of Dragons. Another recent show, A Knight of the Seven Kingdoms, follows the story of Ser Duncan the Tall (Dunk) and Aegon V (Egg) and occurs approximately a hundred years prior to the first episode of Game of Thrones. View this post on Instagram Instagram PostBoth shows will return to airing new seasons soon. The third season of House of the Dragon premiere episode will show the Battle of the Gullet, which will also be the most extensive sea battle ever shown in Westeros.A Knight of the Seven Kingdoms renewal of the upcoming second season is also expected to be released in 2027. We are now very near to achieving an extraordinary '15-year' milestone, among other elements, and it is evident that this franchise has many years left for its stories to be told.What does Game of Thrones mean for fantasy television, and what comes next?If fans pause for a minute and consider what Game of Thrones really did to the industry, they will realize that it did a lot of things. Before the show, the fantasy genre on TV was generally considered as a genre that could not generate a sufficient amount of money, and it would never have a large enough audience or great cultural discussions brought about by dramas.The show completely defied all that in a big way, and by doing so, opened up some very closed doors. The subsequent years had a lot of fantasy shows produced by every major streaming service, and while many of the shows were really good, others were not; virtually all owe something to Game of Thrones, which was the first fantasy show of its kind to ever be seen.Meanwhile, the Westeros franchise persists in its expansion while providing additional opportunities for the fans to find more aspects within the universe. It has been ongoing for fifteen years and still continues to run, which is significant.