Game Breaker/Nintendo Wars

Game Breakers in the Nintendo Wars series. Dual Strike in particular is so full of them that the only problem is figuring out which one is by far the worst.

Force and Force/CO combinations (Dual Strike)

 * God Kanbei. That is with most defense boosts and a tag partner with Bodyguard. Kanbei will have a 50% defense boost, which combined with how defense works in Dual Strike makes Kanbei's defense so absurdly powerful as he can just spam infantry and throw in a few indirects.
 * Sami with the force that adds 2 to Capture. This value is set, but this works in Sami's favor, as it's unconditionally 4 extra points on the first two turns of capture (and 2 extra on any subsequent turns, but that's unlikely to happen). What does this mean? This means that if Sami has a full health Infantry start capturing, it just needs to survive to finish capture. (15 + 2 + 1 + 2 = 20) Of course, considering how much you need to spend to conceivably One-Hit Kill her infantry on Cities, you'll never be able to stop her from spamming infantry to easily capture Cities and get out your own support. This is without mentioning that Sami can also equip defensive forces to make things worse.
 * Ignore the fact that if you're not paying attention, she can capture your HQ in one turn!
 * Forest Free reduces the Movement Cost on Forests to 1. Because, you know, Forests should provide defense boosts and no movement issues whatsoever. This force majorly helps to destroy Tactical Decoy on Time Survival.

CO combinations (Dual Strike)

 * Dual Strike brought things to a new level with obscene Tag Team combos. Eagle/Sami get 3 turns with their Tag Power, and on the third Sami can capture any building instantly (and gets a movement boost for infantry to boot). And the game pretty much suggests this with a 3-star rating for that pairing (which means a 1.5 HP luck damage boost on top of all that). Oh, and they have in-game synergy, so their power gets boosted to 1320% (in addition to the infantry offense boost that Sami gets with Victory March.) Meep.
 * Your Mileage May Vary, though, seeing as how their tag power takes a year and a day to charge.
 * Not to mention that they have incompatible strategies in every other respect, which really bungles things up since Eagle has to lead the Tag Power despite Sami being the stronger CO.
 * Tag Breaks can be game-breaking in general. But if you want a worse combo involving Eagle, try Sonja as the second CO. Eagle/anybody gets 3 turns in a row with their Tag Power anyway, and Sonja not only has a shorter meter, but her SCOP effect of counterattacking before being attacked ensures that they effectively have four turns.
 * One Tag Break that can get particularly obscene is Drake/Olaf/Hawke + Drake/Olaf/Hawke (no doubles for a given player, granted). 2 turns is bad enough, but when you consider that the opposition loses 40% of their terrain bonus, health, and attack power, you can see that the only way the counteracting weakness can be suitable is in a very, very crippling manner -- unfortunately not the case. In a team match, if the opponents both use that combo (and yes, multiple players may use the same COs), Heaven help you if they get Tag Breaks back-to-back.
 * Drake + Olaf has the best synergy: Tsunami halves current fuel, and blizzard doubles remaining fuel usage. Most of your enemy's navy and air forces will be troubled by it if you get lucky, although (unlike most other broken tag examples) the tag isn't very powerful day-to-day beyond the hilarious tag break effect. Has the Fan Nickname "Drolaf"
 * Whoamagod, Colin and Sasha are an obscenely powerful pairing. Sasha earns 10% more funds while Colin spends 20% less of them, meaning you'll rarely find yourself at a loss for cash if you swap them out right. Better yet, starting a Tag Break with Sasha means that her Super Power (which earns her money based on the damage she dishes out) basically fuels Colin's (which uses his funds to boost his attack strength). In addition to the 40% power boost and 15% luck boost you get from their tag anyway, this basically translates to "destroy everything foolish enough to get in your way".
 * You don't even need the Tag Break. Gold Rush and Market Crash are both spammable as hell, given they're both two-star CO Powers. And Market Crash can be used to shut down a number of other powerful Tag Breaks like Earth and Sky or "Drolaf".
 * Although God Kanbei (see above folder) is bad enough, pairing him with Hachi or Colin (both Game Breakers on their own) or his daughter Sonja (for a 130% tag and 15% luck boost) are all excellent ways to lose friends. Only other broken tags, like the above-mentioned Colin/Sasha tag, can compete with it.
 * Incidentally, Hachi and Sensei have themselves a one-star tag (110% attack, 5% luck boost), which is also horribly powerful because of both participants' status as individual game breakers. Ironically, this tag has the obvious weakness that both players' most broken abilities only work through having empty cities at the start of their turns, meaning you either let Sensei go first and waste the ability to use freshly bought units from Hachi, or you let Hachi go first and reduce the potential number of mechs (and money gained from combining said mechs) for a Hachi-induced buyfest.
 * If Sensei goes first, all those mechs can get combined on Sensei's turn (they paradrop at 9 HP active on that turn) for more money for a Hachi-induced buyfest on Hachi's turn. Yes, that's as bad as it sounds.
 * Fortunately a Tag is only as strong as its most powerful component CO, meaning a number of them can be beaten by single C Os. On the other hand, all this means is that the Tags with C Os on the high end of the scale vastly outnumber those on the low end.

C Os

 * Unofficial online version Advance Wars By Web has a Banned CO feature during game set up, the most common bans being Colin, Hachi, Grit, Sensei, and Kanbei, together with any COs with a clear situation advantage on a map (such as Javier on a map with more than one Comm Tower per side in play).
 * Organised WFC games of Days of Ruin tend to have the frequently broken Isabella/Catleia banned. Caulder/Stolos is banned too, but that ban's built into the game's random battle feature, as he is the game's Big Bad and was supposed to be horribly broken -- making it ironic that he's the sole CO with a weakness (spending money for the repairs to his units in his zone). Tabitha/Larissa is also considered broken, and her lack of zone and a crippling glitch may not be enough to prevent her from being truly so.
 * Sensei. Dear God Sensei. He has a 2 Star CO Power that spawns Infantry from all of his own Cities. Watch as he fills the 50 unit quota quickly and ends up with self-feeding powers with any decent number of properties. This gets much worse, if that's even possible, in Dual Strike because of Infantry One Hit Kills charging the meter by 2/5 of a star each as opposed to a measly 1/9 in Advance Wars 2. Not only does his meter get charged quickly, especially with infantry being core units, but the powers self-feed beyond belief. And not to mention all of those infantry you have to wade your way through. You'll be wishing at this point you were playing Rondo of Swords, because since you can't work with its Route Maneuver system, AW 2 Sturm would be helpless against this broken old man.
 * But let's not let the Broken Trio or Kanbei off:
 * Colin spends 20% less for his units that get power penalties.......but only a meager 10% firepower penalty. And it gets better: Colin's Gold Rush can be spammed and multiplies his current Gold amount by a whopping 50%. And if he gets out Power of Money, a COP with the potential to give obscene power and indeed likely to do so, with a good amount of money and units on hand, you're dead.
 * Grit has +1 Range for indirects. He has no problem meatshielding them repeatedly, or even having them meatshield each other. His direct-combat units are weaker, but he doesn't need them to keep your army too dead to so much as approach him.
 * Dual Strike "solves" this by having the meter power up so fast that Grit can't muster anything resembling a defense before being bulldozed. Predictably, this creates a whole new set of balance problems.
 * Hachi may not have Sensei's numbers, but he techs up like no one's business. On day 8 most C Os might have a swarm of Infantry, some Recons, maybe even a Tank; Hachi has a Megatank on the front lines and a Black Bomb with your name on it. When most C Os are strapped for funds they tech down to Infantry and Mechs; Hachi techs down to a Md Tank swarm. In an absolute worst case scenario, Hachi can summon more Tanks in one turn than most will build in a whole game session. Simply put, you do not fuck with this man.
 * Kanbei pays more and has stronger units for it. His defense boosts get vicious because of the way defense is handled, because terrain helps him more. It doesn't help that the highest base damage is 120%, meaning that it's even more infrequent to see a One-Hit Kill on any of his units. And as if that wasn't bad enough, his SCOP, Samurai Spirit, provides Nigh Invulnerability.
 * In Days of Ruin, while CO units are generally overpowered, in general, Tabitha will take the cake, and eat it. Thanks to her, the metagame has shifted to land/air maps -- and even on those she's still plenty powerful. The reason is because while she boosts only one unit (later on a limited number of units), that one unit gets insane boosts. If she gets air units, she can CO a B-Copter, which gets any number of One-Hit Kill scenarios on non-expensive units even on terrain, can use its aerial movement to wait for a chance to pounce, and doesn't even die instantly from a non-CO AA unit unless it's one option that is so lopsided it inevitably has a weakness that overcoming requires already beating Tabitha conventionally. This wouldn't be so bad if she needed cover for more than only 2 kills with her CO unit to threaten to get zone expansion, which, of course, gets her a lot closer to her insane CO power -- and God help you if she does get it. The irony is, on maps with land or sea, she can just camp the center with a Light Tank or Battleship respectively because there's no cost effective way dealing with either due to the power boosts.
 * Of course, Isabella and Caulder are far worse, but for reasons that make them clearly more overpowered than other COs. Isabella does the same thing as two COs, effectively obsoleting both of them due to how CO units generally work. Caulder provides the same power boosts as Tabitha to units in his massive zone (same as Brenner's, larger than Tabitha's at full meter), and also provides daily healing to zone units at five H Ps per unit. But then, he's Purposefully Overpowered, which makes it ironic that he's the only CO who even has a weakness at all. (He spends money on his daily healing.)
 * Tabitha's not that bad, since she only buffs herself at first. As powerful as her one unit is, it's only one unit. There's also a glitch (Your Mileage May Vary as to whether it's a horrible nerf or a godsend) that means she doesn't charge during her opponent's turn.
 * Due to Javier receiving a defensive bonus for each Communication Tower he has and defensive boosts being considerable in Dual Strike, any map with 3 or more COM Towers quickly becomes "choose Javier or lose". The added defense bonus from that many towers will turn Javier into an iron wall. Coupled with the Infantry spam tactic, there's almost no way for anyone but Javier to break Javier's defenses, and if both players use Javier on a map like that, a stalemate is bound to occur.
 * Max in Advance Wars 1 gets a 50% firepower boost for his direct-fire units, in return for the -1 range to his indirect-fire units. What is wrong with this? Simple: none of his units have to be indirects. So he can easily eliminate a weakness and end up with plenty of One-Hit Kill potential.
 * The Fake Balance is even worse with Drake and Eagle in that game, as they are skilled respectively in water units and air units, and have weaknesses that are vice versa. This would be all well and good if they ever had to even use those units. In the entire campaign and most of the war room battles, you never once see that happen. So they effectively have no weakness whatsoever, not even a slightly-preference-impairing one like Max.
 * Sturm is Purposefully Overpowered in Advance Wars 2, that much we get, but when you have all valid Movement Costs reduced to 1, which he did even in Advance Wars 1's VS mode where he was supposed to be balanced, you end up here simply because of marathon Recons among other reasons.
 * Dual Strike buffs Eagle into a character who can destroy two Survival modes. His COP, Lightning Drive, which was horrible with meager power boosts for just air units in Advance Wars 2, now instead is Lightning Strike with an attack loss. But only 3 Stars and no defense loss. Just for icing on the cake, Eagle has plenty of room for chargeup. He will tear up characters who don't still manage to be more broken than him.
 * Pretty much the entire game of Dual Strike can be broken down into who is more broken than whom just because of its insane charging system. Indirects are all but useless, direct-attack firepower trumps any luck, movement, or terrain bonuses, mass damage is an auto-win against all of those, etc.

Units
"Xylvania infantry: *sits in position ready for enemy attack*
 * There is the Infantry Spam strategy that has become fairly universal in high-level play, using massive amounts of cheap infantry as protection for your more expensive vehicles.
 * Add in the indirects and you have a force that will never be cost-effectively killed. And it's hard to believe that this is still happening in the Advance Wars games. This shows that in Super Famicom Wars (and Famicom Wars and Game Boy Wars 1/2/Turbo by extension) it gets worse.
 * Not so much in AWDS. Powers charge so fast in that game that Recon swarms can easily nip an Artillery wall in the bud.
 * Mech Flooding in Game Boy Wars 3 and Days of Ruin. When you can't spam the cheapest unit as efficiently, just spam the next cheapest unit, especially if there's no cost-effective counter against a group of the buggers. They were overpowered before Infantry spam was discovered to beat this with cost effectiveness, and in those two games, that's not going to happen. In the former, Mechs have working defense for the fact that they can javelin-fire on armored units, which themselves are overly expensive, not to mention the difficulty in first striking units in this game. In the latter, there simply aren't many things that One-Hit Kill them even off of terrain and they'll cost-effectively wreck anything except a few things that are dealt with by easily built contingency units.
 * Stealths in Dual Strike, while expensive, can immunize themselves to literally every surface unit. This wouldn't be so bad if not for the fact that Stealths can attack anything that isn't a dived submarine. It doesn't help that the Fighter, which can hit the damn thing, costs too much to stop the Stealth from managing enough of its cost, since exposing the Stealth requires already having a unit next to it, so the opponent can just have 3 durable meatshields on its flanks to keep a Fighter from touching it.
 * Stealths might be able to hit nearly everything and be hit by nearly nothing, but their fuel capacity is horrendously low considering that, when hidden, they go through 8 fuel units without even doing anything. They don't have the damage output of regular Fighters or Bombers either. Plus if you remove one of those three meatshields, the Stealth can be spotted and intercepted - frankly not a difficult job considering their low move range. Granted, they can be gamebreaking, but some of the tactical decisions you have to make for them to be effective kinda tip off the enemy to where they are, defeating the whole "stealth" aspect.
 * Black Bombs in the same game are even worse. They do 5 damage unconditionally to every enemy unit within 3 spaces of where it explodes, and if you think you'll build only a few units to keep it from being cost-effective, the opponent will spend all of their remaining money to pick them off. You can't even catch it, as if you try, you will get bombed, no questions asked.
 * Megatanks. Though essentially a Mech with more movement but less gas, they can destroy ANYTHING they set their sights on! In the hands of a decent player (and a CO with high attack), they can wreck Neotanks and foot soldier swarms by just LOOKING at them! And if placed at a captured city or base that doubles as a strategic point/virtual stronghold on ground-unit-only maps, NOTHING can get past them!
 * Well, considering they cost the same as a BATTLESHIP, have a ammo capacity of three, and the fact that you could build a bomber and artillery, five artillery, a Medium tank and two artillery, NINE mechs, or a stealth and a mech & infantry, or four tanks, all of which could easily bypass the one lone city. Alternatively, you could simply leave it alone on the city, surround it with infantry, and bombard the #*!# out of it, while it can only shoot a lone infantry a day, losing a 1000 unit to give the enemy 5600 in repairs every day is a very good trade.
 * Put them in the hands of Jess, however.....
 * Forget Jess, put them in the hands of Hachi. With Merchant Union he can put one of these monsters on a forward city by day 8!
 * In Days of Ruin, in any map with ports but no airports, the Aircraft Carrier's sea planes, which can attack any unit, can quickly become a game breaker. Since the enemy AI always starts out with anti land/sea units, the seaplanes can easily take them down, and even if AA's are brought in they still can do serious damage when attacking them.
 * This actually assumes there's enough money for spare Carriers in the first place.
 * In Game Boy Wars 3, you can generally focus on building up your air force in Campaign. There's the Interceptor to snipe off the enemy air units, the promoted Gunship to tear apart anything on land including Anti-Air Tanks, and the Bomber to bomb the enemy HQ into an easy capture. It's not wise to have too many air units, but when the enemy gets forced to build too many Anti Air units, they'll leave themselves open to the land force. Of course, Interceptors at least are pretty much a necessity. Bombers, however, aren't, and since you deploy units for free in Campaign, you can just ignore the high cost that Bombers have that would stop them from causing HQ captures.
 * Submarines in Game Boy Wars 3, both in Campaign and on the Standard map Raddish Island. The only other unit that can hit them is a freaking helicopter. In Campaign, the helicopter will arrive too late and will most likely be in for a Curb Stomp Battle courtesy of either the air force or the game's generally AA-heavy navy. In Raddish Island, there are no Airports to send out those helicopters. Even Game Boy Wars 1/2/Turbo had a navy unit able to hit submarines, why not Game Boy Wars 3?
 * The first Battalion Wars has Anti-Air Vets, which for being multi-hit along with causing knockback to any land unit except the Battlestation causes high damage with each hit. Want to know how bad this gets? A lone one can solo the two Battlestations in the final mission. That isn't even anything close to within their job description and they manage it anyway, along with cutting down all of the infantry along the way including the Acid Gas Vets -- in fact, Flame/Acid Gas Vets are supposed to do this job. Assault Vets in the first game, as well as Bazooka Vets in the sequel, can't even compare to this.
 * However, let's not let either off the hook, partly because both, like the Anti-Air Vets, are infantry who can pull evasive maneuvers against enemy units, which isn't a bad thing considering the games generally center around infantry, but also because both get overboard with their power:
 * Assault Vets in the first game deal Heavy Tank armor piercing damage with each shot. Of course, this also means that a manually controlled Assault Vet can turn destroying heavy units (except the Battlestation, which is mercifully immune to the bullets) into a game of balance-the-meter to keep shooting rapidly without suffering the overheat. Something is wrong when a lone unit can kill the local Demonic Spiders effortlessly. And something like this that can happen sums it up:

''(Two seconds later, the Xylvania infantry are all dead, with a lone Frontier Assault Vet standing in the middle of the dead bodies and the medpacks.)

Frontier Vet: Never knew what hit 'em!"


 * Bazooka Vets in the sequel have been toned up from the shoddy damage that a lone one deals to Light Tanks. However, problems arise in single player because against infantry, they are Mighty Glaciers, with good potential for One Hit Kills. In addition, a lone manually controlled Bazooka Vet can solo an already nicely guarded Battlestation or 2 Battleships. A lone Mortar vet can solo a Battlestation more easily, but they just run into trouble with evasive infantry. The Lone Bazooka doesn't.
 * Battlestations. Oh god, battlestations. These can easily be used to one hit kill anything except Medium tanks and... surprise, other battlestations. However, you can just snipe the bastards that will cause you trouble. If you're good at aiming with a wii remote, you can take out almost anything before it can get close enough to shoot you. Yes, this includes other battlestations. This troper managed to turn Unwinnable situations around because of this.
 * In Days Of Ruin, a properly-shielded Anti-Tank can become this. The thing has the same range as an artillery, absolutely rips ground vehicles apart, can attack copters, and, unlike any other indirect unit, can counterattack. Its primary weakness is, surprisingly, infantry, but if you have other units poised to take them out before they get too close and have an anti-air or two at the ready to shoot down any bombers or dusters that try to move in, you basically have an unstoppable ground-unit-and-copter killing machine.