- Topple locks. With enough skill levels and gems to extend Topple's duration, the cooldowns for Topple arts will finish before the effects even wear off, allowing the party to keep up an infinite chain of spamming Topple on enemies so that they never even get a chance to get up. It's possible to defeat enemies far above the party's level by cheesing it, as seen here.
- Aside from Sharla, it's possible to tear the game apart as any character with the right setups:
- Shulk: His regular arts are easy to score criticals with if he's under player control. This builds up the Party Gauge rapidly, allowing you to use Chain Attacks very consistently. He even packs a little healing to go with it. And that's not even counting the Monado on top of all that, which on a New Game+ with the Infinity +1 Sword version, has a 75% critical hit rate and by far the highest damage of any weapon. His talent arts with it can allow him to deal heavy damage, seal enemy auras, and defend against their arts, making Shulk the most versatile character in the game.
- Dunban: Is just behind Shulk for the strongest regular attack in the game, and his agility lets him tank just as well as Reyn without needing quite as much healing while almost guaranteeing continuous damage against enemies. He also starts off with the ability to inflict Break -> Topple all by himself, and most of his auras offer incredibly useful bonuses for whatever role you need him to fulfill. Peerless in particular offers a blanket damage boost of as much as 155% to the entire party and for free. Dunban's massive Agility stat also lets him consistently hit and dodge attacks from enemies with a significantly higher level than his own which makes him a vital part of most strategies for defeating the optional Superbosses, which can be augmented even further with his Serene Grace aura.
- Melia: Discharging her spells counts as a neutral art during Chain Attacks, letting her serve as an "adapter" between two characters with otherwise-incompatible arts, making it very easy to get the maximum 5x damage multiplier. She also has a very useful instant-Topple art combo with Spear Break + Starlight Kick. Even though her AI doesn't utilize her to her full potential (and tends to have her get WAY too close to enemies despite her being the least durable character in the game), in the hands of a player, she's probably the hardest consistent hitter in the game and her spell discharges can result in a barrage of lethal damage-over-time ether attacks on top of it.
- Seven/Fiora: Once you've fully unlocked her fourth skill branch, all of her counter-attacks and double-attacks become critical hits. By borrowing Dunban's Critical Drain ability, she can heal herself with practically every hit. In addition, her Sword Drones Talent Art can rack up huge amounts of damage with a full chain multiplier (to the point where it's capable of killing the strongest Bonus Boss in one Chain Attack). Oh, and all her weapons hit Mechon for full damage.
- Riki: This little furball is a monster. He will hit 9999 health before he hits Level 99, letting him tank hits like nobody's business, and his Arts are focused on spamming endless varied status effects and debuffs. Let this Nopon loose, and enemies will have more debuffs than the display can hold, followed by a superpowered Say Sorry. The cherry on top is Riki Is Angry, which reflects and multiplies the damage Riki takes from attacks, leaving the enemies in up to eight times the pain they gave him.
- Reyn: Although his tanking abilities against physical opponents starts to plateau by the late game, and his auto-attack DPS is limited by its slow speed, with the right auras, skills, and gems you can do absurd amounts of damage. Set it up properly and Reyn can kill most enemies with a single well-timed move.
- Of special note for Reyn in the Definitive Edition of Xenoblade; because of the inclusion of a higher arts level cap in Definitive Edition in comparison to the original version, Reyn ended up getting indirectly buffed in a way that turns him into an absolute Topple-Locking God. Through the use of cooldown skill links and with the right set, Reyn can easily keep an enemy permanently topple-locked throughout the battle. Behold! Reyn solo-ing Final Marcus while at level 1.
- Auras that trade one stat for another apply the penalty as a debuff to the character, meaning a full-strength Debuff Resist VI gem will negate it. This is particularly breaking for Reyn, whose Berserker aura applies a defense-reducing debuff to himself in exchange for his Strength being increased by as much as +240%.
- On all versions, there is a way to break into the post-game section of Tephra Cave, which will be completely devoid of enemies but will still grant you experience and landmarks for discovering locations, and there are Ether Crystal deposits that grant crystals that can be made into Level 5 or Level 6 gems, normally not available until the postgame. The experience from discovering all of the locations will super-boost all party members to at least level 50, making the early-to-mid-game a complete joke.
- On non-Definitive Edition versions, a player would either damage-boost themselves off a specific attack, or time a jump at the same time as a block (which was heavily RNG dependent) and it would push that party member onto a raised ledge close to where Shulk sees Reyn fleeing from arachnos. This could be done as early as the first foray into the cave by clipping through the closed door in the ruins area, but was far more luck-dependent. This was patched out of the Definitive Edition by preventing damage knockback while already airborne.
- On the Definitive Edition (as of version 1.0.0), the player can utilize a glitch involving vine-climbing and party leader-switching to clip through a wall close to the Arachno Queen, which would land them on a post-game section ledge, allowing them to essentially go in reverse and discover everything compared to non-DE versions. This could be done as early as the Arachno Queen fight, meaning a bit later in the game, but still enough to super-boost players' levels, and unlike the previous method, this one was far less luck-dependent.
- On all versions, using Melia's sleep and spear break commands, it's possible to push Gogols off the cliff side on Bionis leg, killing them instantly and dropping a chest. While the characters will only get EXP directly proportional to their level regardless to keep from power grinding, the Gogols still drop some pretty good stuff such as great late game equipment, max level art books, and near max level strength up gems that can reach max with some diligent crafting. All this helps save a lot on money and gem space, as you won't need to buy equipment for that piece of armor ever again or even need more than one strength up gem to reach the maximum boost it can give you, and any repeated art books you get can be sold for high amounts of cash.
- Completing nearly every sidequest as quickly as possible as soon as they open up. In order to encourage players to seek out side quests, completing sidequest usually gives you far more EXP than you would from fighting monsters normally. This wouldn't be too game breaking in itself if not for the sheer number of sidequests the game throws at you every time you reach a new area, and several of them being incredibly easy/quick to complete. Ultimately, going for 100% Completion usually results in characters being horrendously over leveled in comparison to what the game expects of you; often with them ~10 levels higher in relation to the enemies in the area, up to including the Final Boss. Money is also a complete non-issue because of this as well. Definitive Edition addresses this by adding Expert Mode, which functions like the Bonus Experience system from Xenoblade Chronicles 2 where Non-Combat EXP is stored for each character instead of being applied immediately, as well as the option to lower a character's level, meaning players who want a challenge won't be discouraged from completing the sidequests.
- Casual Mode in the Definitive Edition can utterly break the game due to the fact you can turn it on and off at will... while still retaining the benefits you gained. It's possible to attack and defeat enemies that're over 20+ levels above you while on casual mode. While already possible thanks to Break-Topple-Daze chains, you don't even need that and can just spam Damage over Time abilities. Especially if you happen to have an evasion tank like Dunban and/or Fiora. Not only does this get you some powerful equipment and skill books, but you also gain experience fast. And this isn't even counting that you can complete quests made for a party with levels in the nineties when you're only in your seventies.
- Using Expert Mode, you can also grind your characters up just about anywhere if you set them to a low enough level that they get extra experience points from defeating higher level enemies.
Game Breaker / Xenoblade