"The only way warp can "work" is if you deliberately design maps that force the player to use warp in certain spots and take the warp staff out of the player's hands in other areas that would otherwise break the game.
The title says it all. Any topic that relates to Fire Emblem is welcome here.
But what about Fates?
That game did Pair Up right, didn't it? Not really. Even if the Fates version of Pair Up is more balanced and better designed than Awakening's, it's still way too powerful. Dual Guard still makes juggernauting relatively easy since the stat boosts that can come from that can still be huge. Slow characters can become fast, characters that deal low damage can kill things, and thanks to the shields becoming consistent, a character with Dual Guard has better survivability.
Recap: Even when it's better balanced, Pair Up makes juggernauting far too easy. It's a mechanic that's so powerful that it always dominates the game's design. There's no drawback to using it, and because the game designs itself with the use of this mechanic in mind, not using it can put the player at a disadvantage.
The Rescue Mechanic
And here we have the more balanced, but still broken, older sibling of Pair Up: Rescue. The rescue mechanic could be best defined as:
"Rescuing allows playable units to pick up allied units – using the Rescue command – who are smaller than them, in order to protect them from harm or to carry them around the battlefield."
(Source: https://fireemblemwiki.org/wiki/Rescue_%28command%29)
Why is the mechanic this high up the list? In the hands of the right player, the rescue mechanic can do a lot! It allows players to move longer distances in shorter periods of time. Remember the # 5 spot on this list? The spot about fliers and mounted units? This mechanic gives them an even bigger advantage over infantry units because this is valuable utility they can use, and take advantage of, that infantry units can't. Fliers can even rescue infantry units across terrain like water tiles and mountains, making fliers even better than before.
Scylla did a great job pointing out another reason why rescue is busted: "Rescue also allows you to be far more aggressive with your positioning because you can just pull a unit out of a bad spot;"
What makes the mechanic even more powerful is when players start implementing rescue chains, where multiple mounted and flying units take a rescued character and ferry them across the map. It's pretty common among faster playthroughs, and this ultimately results in the player being able to beat entire maps in quicker periods of time. It also results in the player being incentivized to use mostly mounted and flying units, which is bad for the purpose of balancing.
Quick Recap: Rescuing is busted because it allows the player to move from A to B in far faster periods of time, erases the negatives of bad positioning, and makes mounted and flying units even better by giving them additional, powerful utility.
Moral of the Story: Ferrying mechanics are super busted, and Fire Emblem as a franchise would do well to remove them from future titles.
It's easy to see the appeal of a mechanic like this: It makes restarting less painful and time-consuming. If you're like me, you probably use this mechanic for this purpose. However, like bonus experience in Path of Radiance, there is a way for a more experienced player to use this in a way that completely breaks the game.
So yeah. This game essentially lets you fish for critical hits, and makes it easy to accomplish. Another issue is that Maddening mode of Three Houses seemed explicitly designed with this mechanic in mind. This led to the game implementing same turn ambush spawns, which is bad design. The next point about time rewinding is that it makes games easier, since resetting is less punitive and that so far the games where it's implemented have been really generous with how many charges the player gets. The obvious solution would be to give the player fewer rewinds on higher difficulties, but so far that hasn't happened.
a) Players can rush forward without any consequences.
b) This mechanic works as a way to force the probability to do what the player wants it to do.
c) It can be used to justify bad map design.
This is a mechanic so powerful that it will inevitably shape how the game plays, which is why it deserves to be so high up on this list.
In addition to that, they usually have partial or total weapon triangle control, rescue utility in some games (we'll get to that at a later post), and powerful skills. It takes a really powerful drawback for these guys to not get used at all. Most Fire Emblem games don't have that. So as a result, pretty much every Fire Emblem game will have at least a few mounted units seeing use destroying enemy units.
Jagens / Oifayes
One of the most notoriously powerful types of cavaliers are Jagens. They're basically the pre-promoted character that joins the player at the beginning of the game. They're typically the best character in the early game. Their stats are better than everyone else's and they have better weapon ranks, which usually translates into more damage dealing since they almost always start the game pre-equipped with Silver Weapons.
In short, these are efficient high movement killing machines. The old school wisdom used to be that your growth units will eventually surpass these guys by the end of the game. The problem here is that this growth takes a long time, and by the time the growth units catch up, the Jagen will have already carried your team for a substantial portion of the game. Base stats are more important than growths when ranking units, and Jagens pretty much always have better bases. Also, what happens when the Jagens growths are good enough to sustain them? That's when you get these guys...
# 8 - Bonus Experience (Path of Radiance)
The next entry on the list of busted mechanics is bonus experience from Fire Emblem: Path of Radiance. Some of you might have read that statement and might be thinking "but bonus experience is in other games besides Path of Radiance. Why is this game being singled out?" We'll get to that.
Bonus Experience is one of those mechanics that sounds like a good safety net idea. Is there a unit who's falling behind? Give them some free experience so that they can catch up with your strongest units. It's a great idea in theory, but there's a problem: That experience can be freely given to anyone, including your best units.
"You can first use Bonus EXP once you reach Chapter 8. You can use a little on Ike and Oscar, Kieran, or even Boyd at that time, but your best bet is to save it for two chapters and immediately pour as much as possible into Marcia. As a flier, she can make good use of it to instantly become a stronger, more mobile version of Titania."
Source: https://fireemblem.fandom.com/wiki/Bonus_Experience
I actually did this during my last playthrough of Path of Radiance. I dumped all my Bonus Experience onto Marcia as soon as I got her, and she mercilessly annihilated the game. This is why Marcia's considered the best unit in the game: She's the best candidate for a bonus experience dump, which is all she needs to destroy the game.
Remember the # 10 entry, Paragon and Veteran? Two skills that let units rapidly accumulate experience? Bonus Experience takes the most broken aspects of those skills, and dials it up to 11. Characters like Marcia and Oscar can instantly promote and be used as a means to obliterate the game. What separates Path of Radiance from Radiant Dawn is that even on Hard Mode (can't speak for Maniac Mode) you're given a BUNCH of Bonus Experience, which allows for things like this to happen.
# 7 - Reclassing
The issue with reclassing is that it becomes very difficult to design the game because the game developers have no idea what the players will have access to at any given moment. How could they? There's a near infinite number of possibilities for any character to be at a given time!
Another major problem is that reclassing can easily make a character really strong with virtually no effort.
Wolf and Sedgar easily become really powerful when reclassed into Generals in Shadow Dragon, Jakob in Conquest can be reclassed into a Paladin, Elise can become a Wyvern, which in turn create new ways for the player to break the game.
To recap, reclassing is a mechanic that makes balancing and designing the game that much more challenging AND it makes it too easy to make a powerful unit.
# 6 - Stride
Increasing movement by one is already very good. + 2 Movement is really good. + 5 is stupid. It makes it super easy to get from Point A to Point B. To make matters worse, Stride is given at an E rank authority in Three Houses! E RANK! Anyone can have Stride from a super early point in the game, and then it'll be there for you the entire time.
The fact that this can boost the movement of up to twelve different characters also allows for even crazier shenanigans to happen. Combine that with a game where anyone can be a flier, and you get a game that's bound to get broken by a savvy player.