These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Ending Fatigue: It is possible by getting the right tactics and training as well as having hundreds of millions pounds worth of cash to afford all the best players that it becomes impossible for opposing teams to beat you. The game technically never ends too.
Then you just go and do it again with another team, for an infinite cycle.
Ensemble Darkhorse: Arguably invoked due to the game being part reality part speculative. Some players who have not achieved anything of note in real life football are very popular with fans of the series due to being great in the game. A short list:
Taribo West. Freddy Adu. Maxim Tsigalko. Fernando Cavenaghi. Freddy Guarin. Billy Jones. Mark Kerr. Cherno Samba.
Others were completely fake players invented as a laugh by researchers in far flung areas, like the legendary To Madiera.
Especially common with younger (21 and under) players. Since it's impossible to know exactly how good a young player will turn out to be, many are much better in the game than in real life. Some examples from this generation include Carlos Fierro, Erick Torres, and Vaclav Kadlec.
Human players can get a major attachment to real-life teams simply because they played a game with them in Football Manager. There are many cases of people in Europe going to see their adopted club live in person and Football Manager being the reason why players in countries without much European football deciding to follow certain big name teams.
8.8: In one of the most idiotic video game reviews of all time, IGN USA scored the 2009 version a 2.0 because the reviewer didn't realise it wasn't meant to play like FIFA or Pro Evolution Soccer. The UK site gave it the usual high score, a 9.1. It caused such embarrassment that IGN had to pull the US review offline completely.
Epic Fail: Football Manager Live was a disaster. One massive issue was completely resetting this supposedly MMO less than a year after launch.
Game Breaker: Abusing some the tactics used in corner kicks could lead your team to score at least once per game in every corner kick (to the point where it's called "fraud corners" in Korea). Versions include:
Stacking the penalty area with all your players. Tell your best long shooter to stand outside the area. If you put enough people in the box teams would often forget to mark the guy standing outside the area. Set corners to go to them and they would bang in a goal every game or two. Freddy Guarin was great for this.
Lesser versions include stacking certain places in the penalty area with your best jumpers so that your 2nd or 3rd best player will get a free run at the near post. Most teams have two tall players in the central defender positions. Many teams don't have anyone as tall anywhere else on the pitch and those that do are often the strikers who stay up the field with the default AI tactics. This means your 1st and 2nd best players at heading will be marked by their only good defenders, leaving your 3rd best player against a short defensive midfielder or full back.
Hype Backlash: Wonderkids rarely attain the heights that they are predicted to in this game. Maxim Tsigalko, Cherno Samba, Mark Kerr (in fact, the whole list above), Antonio Cerrajero, Sherman Cardenas, Nicolas Millan.
I Knew It: What fans of the series get to proudly tell their friends one of those wonderkids turns to be as good in Real Life as in the game. A lot rarer than you would think, Sturgeon's Law is in full effect. Only some (Akinfeev, Falcao, Higuain, Aguero, etc.) become as good as they are in-game.
Or inverted, where a fan dismisses the ability in real life of a highly rated youth player because that player failed to perform for them in Football Manager, and was justified later in that players career.
Memetic Mutation: Pretty much every line from the News section has been subjected to this. Those are often used in Fantasy Football games.
Moment Of Awesome: Again like in the real world of Football, the game is designed so you can amass several personal CMOA's over the course of it. Things like coming back from defeat to win a Cup Final with seconds to go or scoring seven or eight goals in a match for example.
Scrappy Mechanic: Club chairmen are particularly obstructive. "Oh, you took our club from the Conference to the Champions League, and made us the richest club in the world? Good for you. We're not expanding the stadium, though."
The new training module in FM 2013 was widely panned by long term players as it replaced an indepth system that the manager had complete control over what players trained and how hard, into a paint by numbers drop down preset system that wasn't at all able to be modified by the player.
Pre and post-match interviews have been widely complained about ever since they appeared. In fact, venture onto the Dugout and you'll easily find complaints about how repetitive, boring and unoriginal it is, each year there is a demand to overhaul the system and nothing happens.
The various "bottom to top" challenges, known as Country Hero achievements on Steam. Example, English Hero, where your goal is to take a team from the lowest playable league, the Blue Square North/South league, all the way to the English Premier League, 6 divisions above the start.
Another unofficial challenge much-loved by players is the Pentagon Challengenote i.e win the UEFA Champions League, AFC Champions League, CONCACAF Champions League, the Copa Libertadores and the CAF Champions League, which can also suck up hundreds of hours of gameplay.
The Youth Academy Challengesnote basically Country Hero with the added caveat that you cannot sign any players, but must instead work your way up the ranks using only products of your club's Youth Academy. are also powerfully popular and powerfully hard, many attempts replicate the Country Hero challenges, which are even more difficult than usual due to the woeful level of the youth team players involved when starting at the lowest tiers of the game.
Since Sir Alex Ferguson retired, trying to duplicate his career in FM has had a spike in attempts.
The Country Hero is taken Up to Eleven by the long running unofficial "Dafuge" note so named after the username who created it and latter become the head moderator of the "Challenges" section Challenge. Not only do you have to take a team from the bottom league to the English Premier League, you have to take a team who got promoted to that bottom league note Which often means a completely blank team, with no staff, non-existent training and club facilities and a tiny stadium with no seats, and they have to win the English Premier league and the Champions League to complete it. The vast majority of players give up or fail. It takes the best players hundreds of hours to complete it at a minimum. Some constantly reload the game until they get one of the weaker teams being promoted to make it just a bit more challenging.