History GameBreaker / XCom

** Amongst the Gene Mods in ''Enemy Within'', the Mimetic Skin. It's even more broken than the Ghost Armor, an already broken armor in the game, as it allows risk-free scouting for your troops. The only thing limiting about it is that the unit must be at full cover and that once they see an enemy and they attempt to move, the enemies will go directly towards opposite directions. The one exception? Snipers (again) thanks to their "Low Profile" perk (or, for that matter, any lucky operative who gets Low Profile due to Training Roulette). In fact, get a Sniper with Snapshot (that did get buffed by negating its penalty aim by -10), go near any cover, and either shoot and kill enemies with the ITZ or set up your other squad mates and wait for the next turn. And it ''doesn't run out and that unit is still in stealth mode'' as long as said unit hasn't made a move yet. In fact, they're the better recon team ''than assaults'' in this case. Problem with the -10 penalty aim? Just equip a "Scope" to your Snapshot sniper to negate the penalty aim. The only downside is that it costs an ungodly amount of MELD (''65'' meld + 150 credits for that single augment where the other mods cost less than 35 Meld!) to give to one person thanks to an early patch.

** To lesser extent, the repeater weapon mod. The mod causes any weapon strikes made by the soldier to have a chance to be a OneHitKill, with the highest level mod to be 15% chance. This ignores armor or anything else and it works even when the target is a Sectopod or [[spoiler: Avatar]] and even when said hit is a [[ScratchDamage glancing blow from the stock upgrade]]. In addition, if weapon with a Repeater attached inflicts Poison or Fire damage on an enemy via the specialized ammo types, the lingering damage inflicted by the statuses inflicted by that weapon have additional chances to instantly kill thanks to the Repeater. Yes, this means that that Lancer you hit with Venom Rounds can randomly drop dead at the end of your turn because the poison damage will also work with your Repeater. Firaxis fixed this in an update so Repeaters can only trigger on actual attacks.

** To lesser extent, the repeater weapon mod. The mod causes any weapon strikes made by the soldier to have a chance to be a OneHitKill, with the highest level mod to be 15% chance. This ignores armor or anything else and it works even when the target is a Sectopod or [[spoiler: Avatar]] and even when said hit is a [[ScratchDamage glancing blow from the stock upgrade]]. In addition, if weapon with a Repeater attached inflicts Poison or Fire damage on an enemy via the specialized ammo types, the lingering damage inflicted by the statuses inflicted by that weapon have additional chances to instantly kill thanks to the Repeater. Yes, this means that that Lancer you hit with Venom Rounds can randomly drop dead at the end of your turn because the poison damage will also work with your Repeater.

** It's generally agreed that the Grenadier is the most overpowered starting class, mostly due to how powerful and how useful grenades are in the game. Grenades deal guaranteed damage, shred armor, destroy cover, AND can hit multiple enemies at once. Grenadiers can take skills and upgrades that allow them to shoot grenades farther, carry more grenades, shoot multiple grenades in a single turn, AND deal more damage with grenades. This isn't even getting into the special grenades you can develop like proximity mines, acid grenades, incendiary grenades, gas grenades, and more!

*** For [[LongRangeFighter Sharpshooters]], Serial and Fan Fire. Serial makes every kill made with their primary weapon a free action, effectively making it a RANGED version of Reaper and arguably ''better'' than In The Zone from Enemy Within as it even works on enemies in cover, limited only by the clip size and accuracy of your weapon (which can also be alleviated with extended magazines and autoloaders). Fan Fire is Rapid Fire taken UpToEleven, being 3 pistol shots instead of 2, ''all of which are counted as a single move'', meaning that they have 1 hit chance, and will only cause a reaction from enemies AFTER all the shots connect. Now keep in mind that Special Ammunition stacks with pistol damage from Gunslinger-type Sharpshooters, and you'll see that a Fan Fire burst from a gunslinger with Bluescreen ammo will ''shred'' mech enemies. Another Sharpshooter skill, Face-Off, allows them to take potshots at all enemies in range with their pistol, no matter how many of them there are. This skill, when used corractly, will not only allow you soften up multiple pods of enemies at once, but can result in truly mind-blowing numbers of aliens slain with your sidearm in one non-stop chain of pistol shots. There are reported instances of player managing as many as six to nine kills with a single use of Face-Off.

*** For [[LongRangeFighter Sharpshooters]], Serial and Fan Fire. Serial makes every kill made with the primary weapon free of cost, effectively making it a RANGED version of Reaper and arguably ''better'' than In The Zone from Enemy Within as it even works on enemies in cover, limited only by the clip size and accuracy of your weapon (which can also be alleviated with extended magazines and speed loaders). Fan Fire is Rapid Fire taken UpToEleven, being 3 pistol shots instead of 2, ''all of which are counted as a single move'', meaning that they have 1 hit chance, and will only cause a reaction from enemies AFTER. Now keep in mind that Special Ammunition stacks with pistol damage from Gunslinger-type Sharpshooters, and you'll see that a Fan Fire burst from a gunslinger with Bluescreen ammo will ''shred'' mech enemies.

*** [[SupportPartyMember Specialists]] get Restoration or Capacitor Discharge, both skills [[UpToEleven being upgraded versions of the first skill in their respective trees]]. Sounds boring? WRONG. Restoration is, ''in sequence'', Stabilize, Revival Protocol and Medical Protocol ON ALL SQUAD MEMBERS IN THE SPECIALIST'S SIGHT RANGE, whilst Capacitor Discharge is [[AlwaysAccurateAttack Combat]] [[ArmorPiercingAttack Protocol]] turned AoE with a flashbang thrown in, which can effectively render mobs of enemies impotent, whilst ''outright killing most robotic enemies''.

** To lesser extent, the repeater weapon mod. The mod causes any weapon strikes made by the soldier to have a chance to be a OneHitKill, with the highest level mod to be 15% chance. This ignores armor or anything else and it works even when the target is a Sectopod or [[spoiler: Avatar]] and even when said hit is a [[ScratchDamage glancing blow from the stock upgrade]]. In addition, if weapon with a Repeater attached inflicts Poison or Fire damage on an enemy via the specialized ammo types, the lingering damage inflicted by the statuses inflicted by that weapon have addition chances to instantly kill thanks to the Repeater. Yes, this means that that Lancer you hit with Venom Rounds can randomly drop dead at the end of your turn because the poison damage is also affected by your Repeater.

** To lesser extent, the repeater weapon mod. The mod causes any weapon strikes made by the soldier to have a chance to be a OneHitKill, with the highest level mod to be 15% chance. This ignores armor or anything else and it works even when the target is a Sectopod or [[spoiler: Avatar]] and even when said hit is a [[ScratchDamage glancing blow from the stock upgrade]].

* In ''VideoGame/XCOM2'', you can build an Advanced Warfare Center facility which, along with accelerated healing for your soldiers, will grant your soldiers one random skill outside of their class on a random level up. Depeding on the class and skill synergies, this could result in very broken builds.

** Amongst the Gene Mods in ''Enemy Within'', the Mimetic Skin. It's even more broken than the Ghost Armor, an already broken armor in the game, as it allows risk-free scouting for your troops. The only thing limiting about it is that the unit must be at full cover and that once they see an enemy and they attempt to move, the enemies will go directly towards opposite directions. The one exception? Snipers (again) thanks to their "Low Profile" perk (or, for that matter, any lucky operative who gets Low Profile due to Training Roulette). In fact, get a Sniper with Snapshot (that did get buffed by negating its penalty aim by -10), go near any cover, and either shoot and kill enemies with the ITZ or set up your other squad mates and wait for the next turn. And it ''doesn't run out and that unit is still in stealth mode'' as long as said unit hasn't made a move yet. In fact, they're the better recon team ''than assaults'' in this case. Problem with the -10 penalty aim? Just equip a "Scope" to your Snapshot sniper to negate the penalty aim. The only downside is that it costs an ungodly amount of MELD (''65'' meld + 150 credits for that single augment where the other mods cost less than 35 Meld!) to give to one person thanks to an early patch.

** {{Spiritual Successor}}s ''[[UFOAfterBlank UFO: Aftermath]]'' and ''Aftershock'' had warp weapons. Subverting the previously established player knowledge of armor=longevity, warp weapons inflict ''greater'' damage if the target is wearing armor. Devastating when first encountered, when the weapons are reverse-engineered by the player, they become the single most devastating weapon in the game, capable of one-shot killing ''anything'', as enemies are ''always'' wearing heavy armor at that point. Greatly toned down in ''UFO: Afterlight'', as the player only gets two warp weapons, with six shots each that can't be recharged during a mission and low base accuracy.
*** ''UFO: Aftershock'' has psionics with level 3 sniper, using the .50 calibre rifle with accuracy add-on and accuracy boosting psi-gear has a 1.1 - 110% chance of a torso hit. A headshot is merely 100% chance of instantly killing the standard mutant or [[ScaryDogmaticAliens Wargot]]. Also you can field a whole team of these girls, and depending on the status of your install the accuracy aura buffs may stack. Gets more insane if you give them Katanas against [[ButtMonkey Wargots]] in room-to-room combat...

*** That being said, MEC Troopers are ''designed'' to be unbelievably powerful in the early game. Conversely, they get upgraded much slower than your normal troops, with fewer weapon choices, no ability to swap out upgrades (i.e. if you get the flamethrower, you cannot get the kinetic strike module without building another MEC suit), and prohibitively expensive costs. You will guard your MEC Troopers religiously because, despite their high initial HP, if they die, you will be out a ''lot'' of money and Meld.

** Ontop of this, the Training Roulette and Save Scum Second Wave options can easily become this. Save Scum re-seeds the game when you load a saved game, thus allowing you to keep taking your turn until you get the exact result you want. Training Roulette allows for some unholy cross-class combinations - Snipers with Squadsight, HEAT Ammo and Disabling Shot are possible, and may god help your enemies should he be found to be Psychic or given Gene Mods...
** Amongst the Gene Mods in ''Enemy Within'', the Mimetic Skin. It's even more broken than the Ghost Armor, an already broken armor in the game, as it allows risk-free scouting for your troops. The only thing limiting about it is that the unit must be at full cover and that once they see an enemy and they attempt to move, the enemies will go directly towards opposite directions. The one exception? Snipers (again) thanks to their "Low Profile" perk. In fact, get a Sniper with Snapshot (that did get buffed by negating its penalty aim by -10), go near any cover, and either shoot and kill enemies with the ITZ or set up your other squad mates and wait for the next turn. And it ''doesn't run out and that unit is still in stealth mode'' as long as said unit hasn't made a move yet. In fact, they're the better recon team ''than assaults'' in this case. Problem with the -10 penalty aim? Just equip a "Scope" to your Snapshot sniper to negate the penalty aim. The only downside is that it costs an ungodly amount of MELD to give to one person thanks to an early patch.

** Amongst the Gene Mods in ''Enemy Within'', the Mimetic Skin. It's even more broken than the Ghost Armor, an already broken armor in the game, as it allows risk-free scouting for your troops. The only thing limiting about it is that the unit must be at full cover and that once they see an enemy and they attempt to move, the enemies will go directly towards opposite directions. The one exception? Snipers (again) thanks to their "Low Profile" perk. In fact, get a Sniper with Snapshot (that did get buffed by negating its penalty aim by -10), go near any cover, and either shoot and kill enemies with the ITZ or set up your other squad mates and wait for the next turn. And it ''doesn't run out and that unit is still in stealth mode'' as long as said unit hasn't made a move yet. In fact, they're the better recon team ''than assaults'' in this case. Problem with the -10 penalty aim? Just equip a "Scope" to your Snapshot sniper to negate the penalty aim.

** But wait, there's more: The ability Opportunist removes the aim penalty for overwatch and other reaction shots, and allows reaction fire to score {{critical hit}}s. This means that if a sniper is on overwatch, and the enemy comes in sight of the sniper (or with Squadsight, any player on the field and there is an open shot between enemy and sniper), it's a much easier and deadlier hit. And then there's In The Zone and Double Tap, the final abilities: In The Zone allows a sniper to take an extra attack if the last shot was made at an uncovered or flanked enemy. Combined with Archangel armor, this can destroy an entire attacking force in one turn, at the risk of your own sniper being out of cover. Double Tap allows a second shot if your sniper doesn't move on his turn. This means your sniper can fire twice if he doesn't move. Once a sniper is in a good position to attack, he no longer needs to move, and on many maps (even the really big ones) it's possible for your sniper to be on one end of the map, and take down with devastating accuracy enemies on the opposite end. Three snipers at Colonel rank with Plasma weapons can fire at least 6 shots a round, with each shot doing enough damage to guaranteedly drop anything less powerful than a Chryssalid with one shot (and they can still land OneHitKills against those.) Enemies typically travel in groups of three, meaning that unless you get attacked by 2 or more groups at once, you can wipe them all out with shots to spare. If your team is half Snipers, half Assaults, your assaults can track down enemies quickly and your Snipers can pick them off as they are found.

** But wait, there's more: The ability Opportunist removes the aim penalty for overwatch and other reaction shots, and allows reaction fire to score {{critical hit}}s. This means that if a sniper is on overwatch, and the enemy comes in sight of the sniper (or with Squadsight, any player on the field and there is an open shot between enemy and sniper), it's a much easier and deadlier hit. And then there's In The Zone and Double Tap, the final abilities: In The Zone allows a sniper to take an extra attack if the last shot was made at an uncovered or flanked enemy. Combined with Archangel armor, this can destroy an entire attacking force in one turn, at the risk of your own sniper being out of cover. Double Tap allows a second shot if your sniper doesn't move on his turn. This means your sniper can fire twice if he doesn't move. Once a sniper is in a good position to attack, he no longer needs to move, and on many maps (even the really big ones) it's possible for your sniper to be on one end of the map, and take down with devastating accuracy enemies on the opposite end. Three snipers at Colonel rank with Plasma weapons can fire at least 6 shots a round, with each shot doing enough damage to drop anything less powerful than a Cryssalid with one shot. Enemies typically travel in groups of three, meaning that unless you get attacked by 2 or more groups at once, you can wipe them all out with shots to spare. If your team is half Snipers, half Assaults, your assaults can track down enemies quickly and your Snipers can pick them off as they are found.

*** No longer this in ''Enemy Within'' due to the new enemies introduced avert the ComplacentGamingSyndrome. Seekers, specifically, are introduced to kill isolated snipers releying on squadsight.
**** Unless you give them one of the new Gene Mods which shocks them if they try to grad the sniper, or are wearing heavy armor, such as the Archangel armor... Which allows a unit to fly and only uses move. Meaning you can fly the Sniper straight up into the air and cover almost the whole battlefield.

* Not to mention ''X-Com Apocalypse'''s Toxigun. An insanely powerful weapon that costs just a pair of APs per shot to fire and completely surpasses the aliens' Disruptor Shields. After researching this and the Personal Teleporter, the game pretty much turns into administering point-blank euthanasia shots to the aliens. Even more ridiculously overpowered Alien Gas Grenades and Alien Gas Rockets are available late in the game, provided you manage to [[spoiler:capture the Alien Queen live]]. The [[TeleportersAndTransporters Personal Teleporter]] allows you to instantly teleport your soldiers anywhere on the map, and it is not uncommon to [[SingleStrokeBattle win the mission on the first turn]] considering that your soldiers are likely [[PersonOfMassDestruction people of mass destruction]] by the time you research this item.

*** No longer this in ''Enemy Within'' due to the new enemies introduced avert the ComplacentGamingSyndrome. Seekers, speficially are introduced specifically to kill isolated snipers releying on squadsight.

*** Oh, and with In The Zone, this allows you to devastate the most dangerous enemies in the game: Chyssalids, Ethereals, Muton Berserkers, and Sectopoids. All four ignore cover, so with a full clip, it's possible to just unload with sniper shots until they die.

*** You can actually stick any craft weapon on any ship capable of dogfighting. Cue the Plasma Cannon: not overly powerful or fast, but its range exceeds that of any UFO except the largest Battleships, its ammo is free, and it has plenty of the stuff. And you can order your craft to fire from their maximum combat range, hence making even your lowly Interceptors effectively invulnerable. Battleships are immune to this tactic and do deal massive amounts of damage, but this can be mitigated by attacking them with multiple ships at the same time - the damage gets spread out (dividing repair times amonst the ships present) and the UFO goes down faster (meaning it deals less damage in the first place).

** Avenger/Leviathan craft. Though the basic interception unit is so weak that * every* alien craft can outrun it, these two can outrun and outgun even the strongest alien craft - with a bit of a twist: if they survive, they become TOTALLY USELESS for about a month until repairs are done (plus they consume valuable resources to even keep flying). Meanwhile, aliens are happily wreaking havoc...

*** You can actually stick any craft weapon on any ship capable of dogfighting. Cue the Plasma Cannon: not overly powerful or fast, but it's range exceeds that of any UFO except the largest Battleships, it's ammo is free, and it has plenty of the stuff. And you can order your craft to fire from their maximum combat range, hence making even your lowly Interceptors effectively invulnerable. Battleships are immune to this tactic and do deal massive amounts of damage, but this can be mitigated by attacking them with multiple ships at the same time - the damage gets spread out (dividing repair times amonst the ships present) and the UFO goes down faster (meaning it deals less damage in the first place).

** With Enemy Within, we now have the MEC Trooper, the single most overpowered thing in the game. It's Minigun will shred virtually any early game enemy it encounters, the Kinetic Strike Module can One Hit Kill anything short of a Cyberdisk, Sectopod or Mechtoid, the Flamethrower is easily one of the best AOE attacks in the game (and has the bonus benefit of ''spreading the flames further than the Cone intended'', as well as panicking anyone hit by it) despite it's limited Ammo use, and this is before having a special Class ability. ''And this is just the Mark I, unupgraded model''.

* Psicorps in ''{{X-Com}}: UFO Defense''. Hard as hell to acquire, as you need to capture a psi-using alien that is blasting you with said psi-abilities ([[TheComputerIsACheatingBastard often straight at the easily affected guy that it can't even see]]), interrogate the alien, research the tech, build the required buildings, then wait until the month ends for results from said building. If you're ''extremely'' lucky, you'll have this by the 4th month, else you might have to wait until the lategame aliens show up. But it was well worth it. First off, you get to see the Psi-Defense stat of your units, eventually allowing you to get a team entirely immune to psi-attacks. The abilities themselves are powerful as well. The more accurate skill causes the target to panic, making them an easy kill. The other skill is Mind Control, a skill so powerful that you can use it to win the final mission ''on the first turn singlehandedly''. Apocalypse nerfed it from GameBreaker to merely stupidly powerful (the second was merely so hard [[NintendoHard you actually needed it to win on the higher levels]]). You can use it to mind-control a zombie, kill it, then you have a pet Chrysalid.
** And then there's the [[{{BFG}} Blaster Launcher]], a weapon that could send a missile out the door of your transport, over the heads of your units, down through the door of the UFO and up the elevator shaft to [[DungeonBypass blow a hole]] in the otherwise impregnable UFO hull material. Or alternately just take out a [[HumongousMecha Sectopod]] in one shot. It's successor, the DPT Launcher, was nerfed in a way you can only fire it underwater... unless you consider that you troops can still reaction-fire it! Not to mention that one of the resources necessary to make ammo for it is more abundant in the sequel.