As the first game in the series, it's missing a lot of mainstay elements and has its own oddities.
- There's no Weapon Triangle (swords beat axes, axes beat lances, lances beat swords).
- Visually, in the name of saving space for a large cast, many characters share portraits to some degree, having either modified portraits or outright identical ones. This includes some main characters, with Gharnef being a modified Bantu and Michalis being a modified Navarre. Future games would also recycle portraits at times, but generally only for minor bosses, with the practice dying out in the GBA era.
- Healing classes don't get EXP for healing, instead gaining EXP from dodging or taking hits. To seemingly compensate for this, most healers have very little need to level up, with most of them having abysmal growths and enough Weapon Level to use nearly every staff (with the exception of Wrys).
- There are only 4 items slots per unit instead of 5, and units cannot give items to ally units with full inventories. On top of this, units' turns end immediately after they finish trading or equip a weapon.
- Promotion/class changing works very differently in this incarnation.
- In general, class changing is treated as a rather more secretive and uncommon affair than in future games. The needed items are much rarer, and show up much later: you get your first Hero Crest in Chapter 10, your first Knight Crest and Orion's Bolt in Chapter 12, and your first Bishop Ring and Skydrake Whip in Chapter 19. In addition, the list of classes who can promote is much shorter; Pegasus Knights, Cavaliers, Archers, Mages, Priests, and Mercenaries are the only ones capable of doing so. Curiously, there do exist classes that seem like the promotions of Hunter and Knight (Horseman and General), but they would not be made possible promotions until Mystery of the Emblem.
- By extension, this makes Marth one of the only Lords in the series who cannot promote at all (well, barring Sigurd, who is prepromoted). Later Lords would either promote normally or through a story event.
- Instead of causing a character to gain stat bonuses, promotion raises their stats to be equal to the class bases of their new class. This means that attempting to delay a character's promotion to gain more levels can cause them to gain no stats at all after promoting, making early promotion highly preferable.
- Likely as a result of the above, promoted classes have significantly higher base stats relative to their unpromoted counterparts, compared to other games in the series. For instance, Paladin goes from 8 base Strength and 11 base Speed here to 7 base Strength and Speed in Mystery of the Emblem, and Bishop goes from 14 base Speed to 4.
- Pegasus Knights become Dracoknights when they promote. This also means that Macedon is one of the only nations in the series that has their military made up of both flying mounts, making it split in two between Minerva's Whitewings (who sided with Marth) and Michalis' Dragoons (the side that stays with Dolhr after his sisters' defection). Later games made the two of them distinct Character Classes with their own strengths, weaknesses, class family, and factions.
- The Mercenary and Myrmidon class lines were originally a single class line, using the names of the Mercenary-family classes but functioning like a blend of the two. (The two weren't properly split until the sixth game.)
- Knights and Pegasus Knights were able to wield both Swords and Lances, as opposed to being restricted to one weapon type. Generals are a pure sword class, when every game from Gaiden onward made them either a multiweapon class or a primarily lance-using class.
- Archers were a bit off: most artwork and sprites depicting them with fairly heavy armor, along with the Archer's lower Movement and oddly high Defense, suggest that it was meant to be the Mighty Glacier of the various bow classes. Most Archers since then fit the Fragile Speedster mold, with little if any body armor, equal Movement to other foot classes, and low Defense—a general design originally associated with the Hunter class, which hasn't been playable since in any game not taking place in Archanea.
- This game, along with its remake, is the only one in the series in which Shooter/Ballistician is a fully usable class for players. In future games, they're enemy-exclusive, barring a surprise reappearance in Fates. Additionally, the way ballistae work is quite different: they have a range of 2, just like archers, their weapons have comparable durability to other ranged weapons, and they are used little differently from standard enemies, resembling the later Bow Armor in their implementation. One map, Wooden Cavalry, features an enemy roster almost entirely comprised of ballistae. In future games, ballistae have massive ranges of around 3-10, tend to have only a handful of shots at the ready and are effectively features of their map, frequently being outright stationary. Quite a few future games wouldn't have a dedicated ballista enemy at all, turning the ballista into merely a weapon archers could use while standing on certain tiles. Capping it off, one of the weapons the ballista can be equipped with is very obviously a cannon: one of the only times in the series where a gunpowder-based weapon shows up.
- Xane's class, known as Freelancer, Chameleon, or Commando depending on your choice of translation, is a class capable of transforming into other units and fully copying their stats and abilities. It has never appeared in any non-Archanea game, though some have theorized it to be in some manner a prototype of the Dancer class.
- Some stats have noticeably different functions. HP, Strength, Defense, and Movement work just as how they always do, but most others are off in some way. In rough order of how much they've changed:
- Skill adds just itself to your hit rate with physical attacks, when every game since Mystery of the Emblem has instead multiplied it in some way (usually x2, sometimes x1.5). Also, it doesn't boost your hit rate with magic at all. This means that a weapon's base accuracy tends to be more important than the user's skill, though many enemies have bad Avoid. It does increase crit rate at the usual value, though.
- Like Skill, Speed only increases your dodge rate by 1 per point, when it's been x2 or x1.5 in pretty much every game post-Genealogy of the Holy War. Much more notable, however, is that doubling thresholds are much lower; in most games, you need to outspeed the enemy by a certain number (usually 4, but 3 and 5 aren't unheard of), but here, you only need to outspeed the enemy at all. There is also no way to reduce a weapon's weight, as Strength does not serve that purpose and Constitution does not exist, making it effectively a variable Speed penalty. Because of this, an individual unit's Speed tends to matter far less for doubling than the weapon they're carrying, and many enemies can have 0 Speed.
- Resistance does its usual thing of blocking magic damage, but nearly every single character has a flat 0 in it, making every magic attack effectively a Fixed Damage Attack. The main way to increase it is to use Barrier or Pure Water (which raises it to 7 but decreases it over time). Notably, what the Talisman statbooster actually does behind the scenes is give your unit the same effect as those two but with the decreasing removed. Not only does this make Resistance the only stat to cap at 7, but it also means a character can only have 0 Resistance or 7 Resistance.
- Luck does not increase hit rate (introduced in Thracia 776) or physical avoid rate (introduced in Mystery of the Emblem) or reduce an enemy's crit rate (Mystery again). Instead, it increases crit rate to the same degree as Skill, and improves a character's Avoid when dealing with magic attacks. Incidentally, this means that there is no way to reduce critical rates; thankfully, most enemies have 0 Luck and abysmal Skill, but keeping your units safe from crits is still a concern.
- Lastly, there's a stat called Weapon Level, which serves as the game's equivalent to Weapon Rank (a system introduced in Genealogy and largely standardized in Thracia). Instead of increasing with use, it levels up by chance like any other stat. For instance, any character who can use swords and has a Weapon Level of 9 or better can use a Silver Sword. This applies to all weapons a character can use, as well; characters are always equally skilled with every type of weapon they can wield, making multiweapon classes like Paladins, Dracoknights, and Bishops incredibly strong. Capping it off, it's generally much easier to wield high-rank weapons, with many unpromoted characters being able to use them at base or after one or two lucky levels on a 60-70% growth.
- While most games following the introduction of weapon triangle made the physical weapon types roughly balanced to each other on paper (i.e. every type comes in iron, steel, silver, and legendary varieties, plus a few gimmicks each like effective weapons or magic weapons, and have advantages and disadvantages, usually with swords being the most accurate and axes being the strongest), this game makes no attempt at all to balance them. There are eight available swords plus three locked to Marth, compared to five types each of lances and axes, and swords weigh far less than the other weapon types in a game where weight can't be counterbalanced. Also, the standard axe and hand axe weigh more and deal less damage than the standard lance and javelin, silver axes do not exist (and neither do steel lances), the only equivalent to a legendary axe is the Devil Axe, and there's only four axe-users in the game, none of whom can promote—you can't even buy new axes after Chapter 9. Similarly, the silver lance is straight-up inferior to the silver sword.
- The game's equivalent to the iron axe and iron lance are simply named "Axe" and "Lance." Swords are the only weapon to get their materials named.
- The bow line features an expensive crossbow-like weapon called the Bowgun, boasting high accuracy and and an elevated crit rate with might in between the iron and steel bows. The only other Fire Emblem game to feature the Bowgun is Radiant Dawn, where it is part of the crossbow class of weapons and functions differently, and these two are the only games in the series to feature any mechanized bows.
- The various magic types are not segregated at all. While it's not uncommon for the Anima tomes to be lumped into one category, Aura, Starlight, Imhullu, and Swarm are in the same category, when in later games, they'd be classified as Light or Dark. Additionally, Cleric/Priest and Mage both promote into Bishop; the idea of them having separate promotion paths was introduced in Genealogy.
- Item durabilities are much less symmetrical than the now standard "multiples of five" setup, and weapons weren't divided as cleanly into sets of equivalent power tiers as in later games.
- Enemy units have a stat that displays how much EXP they are worth. In addition, any recruited enemy starts with the experience they had. EXP earned from battles that don't result in enemy kills is determined by how much damage dealt by player units, capping at 20. By extension, this means that EXP gain does not scale to level in any way; a level 10 Paladin gains the same amount of XP from killing an enemy that a level 1 Cavalier does, meaning that prepromotes can actually gain levels fairly quickly.
- There are no class- or character-specific stat caps, so all characters can max out at 52 HP and 20 for every other stat, even for promoted classes. Stats are lower overall, as well, with many characters being able to perform happily at the endgame with stats in the 13-18 range, which would be viewed as midgame stats in most games to follow.
- Stat-boosting items give a boost of 4-7 points to their respective stat. Later games nerfed them considerably between higher stat caps and lowering the potency of the boosters.
- If you decide to send a unit into an arena, they will enter with whatever weapon they have equipped at the time, and will degrade its uses with each round of combat, which can potentially leave your unit defenseless if you're not careful. Add the fact that there's no way to yield a fight in the arenaNote, and this makes using the arena a very risky venture. Conversely, the arena also gives a ridiculously high payout, up to ten times what you bet, when in later games, that number is only double.
- In most games, enemy stats are calculated by taking the class's bases and leveling them through a set of "class growths." This is not the case here; instead, every odd-numbered level after the first, the enemy gains +3 to HP and +1 to Strength, Skill, Speed, Defense, and Weapon Level. Also, enemy levels on the whole are much lower, with few-if-any generic enemies being above level 10. Bosses can be higher-level, but use the same stat calculations.
- By extension, characters recruited from the enemy do not have personalized statlines; they use the same calculations for their stats as regular enemy units. This means that the lower-leveled characters have base stats for their classes, including Minerva, Matthis, Astram, and Wendell. Also, instead of having a preset Luck Stat, their Luck is randomized. This resulted in many characters getting their stats tweaked for Mystery of the Emblem; most notably, Minerva's Speed was doubled, turning her into a Lightning Bruiser, while Wendell's Speed and Defense took some hits.
- In many games in the series to feature a Manakete/Divine Dragon character, their signature weapon is strong against the Final Boss, giving you a fighting chance no matter what as long as you keep them alive. This can make it a surprise to discover that in the first game, Tiki's Divinestone possessed no such properties, being only effective against common dragon enemies—in fact, due to her mechanics, she is literally incapable of damaging the final boss. This can be a shock for people used to the remake, where Tiki being able to knock off most of Medeus's health with a single shot is one of her main qualities. The concept wasn't introduced until Book 2 of Fire Emblem: Mystery of the Emblem (though, oddly, it's not present in Book 1, either). Ironically, New Mystery, the remake of that game, didn't have this going on either, with an explicit in-story justification.
- There are only two unit colors, blue for playables and red for enemies. Neutral "green" units do not exist, with their role being fulfilled by "red" units that have specific commands in their AI—for instance, Darros's AI is programmed to beeline for Marth and then talk to him, at which he becomes playable, and Maria is programmed to sit still and do nothing. Notably, this makes it possible for the player to kill characters like Maria whom they'd have no reason to try to kill, which was even given specific dialogue in Fire Emblem: Mystery of the Emblem.
- Enemy AI in this game isn't radically different from what you'd expect in future titles in the series, apart from one particular quirk: They will always prioritize attacking Marth over any other unit if he is within attacking range. The point of this behavior is that his death will result in a game over, and the intent is to make the game more challenging and force players to be careful with their Lord. In practice, however, this behavior can easily be exploited in unintended ways, as enemies will always disregard Marth's power, and it's not too difficult for him to reach Game-Breaker status. For example, if you have a weak or wounded ally in danger of being attacked by a strong enemy on the next turn, simply move Marth nearby and the enemy in question will walk right past a unit they could've killed to die on Marth's blade. Developers apparently caught wind of how broken this behavior was, as it would not return in any future games.
