Good Bad Bugs/Video Games/Turn-Based Strategy

Examples of in  games include:


 * Worms: With quick fingers it is possible to switch to the rocket launcher and the mini gun at the same time, causing the minigun firing code to fire rockets. There is usually a significant chunk of the level missing afterwards.
 * Colonization has a bug on the trading screen which lets you sell resources that have been forbidden through a Customs House. Naturally, most players don't bother installing the patch to fix this bug, as it makes the game a good deal easier towards the end.
 * In fact, the open-source clone FreeCol reproduced this as an optional rule.
 * The original Civilization had the Settlers bug: if you ordered a Settler unit to perform some multi-turn task (like irrigating or mining a square), it'd usually stay inactive until the task is completed, which e.g. in case of mining a mountain would take up to 9 turns. However, if you canceled its current action and then ordered it to do it again, the engine would interpret it as if the Settler already spent a turn doing it and continue from where it "stopped". This trick could be repeated until the task was complete. Sure, it's a lot of manual clicking but it allowed you to fully irrigate/mine the area around and build roads your city in a few turns, which is crucial at early stages when every Settler counts.
 * You could also put this same Settler on a transport and use this bug to build a road and then a railroad in the middle of the ocean. You couldn't move onto it, but it did give the financial bonus to any city within range.
 * On the contrary, ocean roads bestowed their improved movement on any seagoing unit. A ship could carry cargo halfway across the map if you have a railroad in place for it. You'd have to end a unit's turn when it's loaded into the ship, but other than that you can go very far.
 * In addition, save games did not keep track of which units had already used their turns, so long as you still had at least one unit who had a move left. You could play through an entire turn, save the game, load the save file, and play another turn without letting any other nation get to play.
 * In Civilization IV, getting a Great Person would allow you to expend that unit and put research towards a new technology, initiate a Golden Age, build a unique building, boost your culture, etc. Also added in this game was the ability to give multiple orders at once to a unit, by holding shift while clicking their abilities. It was soon discovered that holding shift and clicking on the abilities of the Great Person did not cause them to be deleted. One game advanced from the Ancient World to the modern Industrial Era through the continual brilliance of Moses. Sadly, this bug was fixed with the expansion packs.
 * In Civ 5, on the higher difficulties, you can leech the gold boost that computer players get by exploiting them with a good army; take over one or two cities, then offer one city back and peace for a whole lot of gold. Go to war 10 turns later, repeat. Usually, conquering a civ only gives you a small fraction of their gold and the rest is lost (for game balance and other reasons), but this way, it can be extracted from weaker civs. This one isn't entirely a Game Breaker since it requires some work and might even make a little sense, besides the computer being far too slow to learn what you're doing (if it ever does). Before the 2011 patches, there were a lot of other ways for players to mess around with numbers in unintended ways.
 * X-COM has a lot of them, some are useful, or can be.
 * Your soldiers may throw grenades through the ceiling. This was incredibly helpful when there was a Muton on the roof.
 * A gem of a bug: Whatever you set the difficulty to, the game played on the 'Beginner' difficulty. This bug went unknown for years, because the game was THAT damned hard. And it gets better: when MicroProse was throwing together the mission pack sequel Terror from the Deep, they solicited feedback from players. A big chunk of players who responded were hardcore strat gamers who complained that the game's higher difficulty levels weren't hard enough. MicroProse's response? Make TFTD's Beginner difficulty equivalent to what Superhuman was supposed to be in UFO Defense.
 * There's also the pathfinding bug in UFO Defense for the blaster launcher, where the majority of the time the enemy units would launch it directly above themselves, even if there was a roof above them, leading to many times in indoor maps where there would be numerous random explosions going on out of your line of sight for, from your perspective, no reason.
 * Tanks have full ammo during Base Defence, even if you don't have it.
 * Ammo automatically pre-loaded into a weapon before mission is weightless.
 * Might and Magic VI has a bug that allows you to turn in a certain quest an infinite number of times and thus giving you infinite experience. All you have to do is keep clicking the quest turn in button without closing the window. This might seem like a godsend, but leveling in that game required you to go train, which costs an increasing amount of gold per level, training to the max level would cost you a huge sum of gold.
 * And as luck would have it, there's an infinite gold bug as well! In each of the 15 outdoor maps there is an obelisk, which displays part of a code which, when figured out, gives the location of a valuable treasure chest. This chest contains the most powerful spells for both Light and Dark Magic, two or three magical artifacts and bestows 250,000 gold on the opener. Then, if you exit the chest and go back in again, you get another 250,000 gold. Repeat until satisfied. Note: Once you leave the chest, the bug stops working, so make sure you get your fill there and then.
 * Might and Magic 2 for the Sega Genesis had a bug where if you dismissed your hirelings before opening a chest, the chest would have ludicrously valuable treasure. Also, in dungeons which didn't let the player use the spell that goes through walls it would sometimes forget it wasn't supposed to allow that, making the final dungeon a cinch.
 * In Might and Magic 7, the player's attack range was slightly longer than the monsters' attack range. Minotaur Lords, which had tons of hitpoints and a ludicrously powerful attack that also had a chance of outright killing whoever it hit, were also very big - big enough that they could get stuck in the scenery in certain places. Combine the two and a player could lure a Minotaur Lord to a chokepoint, get in that range where he could attack it and it couldn't attack back, and carve it up. (Minotaur Lords weren't the only monster this strategy worked on, but because they were so big and dangerous, they're the ones against whom players resorted to this exploit.)
 * Also in Might and Magic 7, you can duplicate some quest items indefinitely. Just put your quest items in a chest somewhere, talk to the Arbiter in Harmondale to get the quest items back, go back to the chest, and repeat. Since quest items have limited use, this may not be very useful. But cool, nonetheless.
 * In Heroes of Might and Magic III, there was a campaign (Rise of the Necromancer) in which you are given two very powerful artefacts; the Armour of the Damned (that makes every enemy weak, slow and useless in battle) and the Cloak of the Undead King (which turned the rather useless skeletons gained from Necromancy into the much more useful, ranged Liches). These allowed you to quickly build up an invincible army of liches that would number in the hundreds by the end of each map. You only get one of each set, but the campaign would also take copies (as well as the component pieces). If you used the Dungeon's Artifact Merchants to gather the components again, you could go through the rest of the campaign with multiple Heroes made unstoppable with these artifacts.
 * The Apple II game Taipan! had the player as the captain of a trading/fighting ship in the Far East. In Hong Kong, one of the ports you could visit, was a moneylender (loanshark) with a ruinous interest rate. Unfortunately for Elder Brother Wu, he didn't understand the concept of negative numbers, so you could borrow 100 and pay him back 200, at which point he'd start paying you interest at his usurious rate.
 * Galactic Civilizations: The diplomacy screen lets you trade basically anything in the game: from single ships and technologies to treaties to entire solar systems. And of course money. Different techs and buildings boost your diplomatic abilities, effectively giving you the upper hand in negotiations, thus letting you acquire more ships for money, or more tech for your money, or - that's right - more money for your money. Things don't stop there, though. You can make contracts where you and the AI pay each other a certain amount for x number of rounds. For some reason this makes both parties richer every round, effectively granting you infinite cash. Another good thing is that the AI just can't handle that much money, utilizing only a fraction of what it has available, while you crank out disgustingly strong fleets in no time at all. Too bad GalCiv doesn't have a multiplayer mode.
 * One of the patches for Master of Orion 2 introduced a very odd AI quirk. Every so often an AI controlled race might notice that your science and military make you significantly stronger than they are. So it would decide you are a threat and declare war on you. A few turns later the AI will take a look at you again and realise they can't possibly win a war against you, so they will ask for peace - often throwing in one of their planets as an incentive. This can happen repeatedly - so the enemy literally hands over their empire to you one planet at a time.
 * In the first Master of Orion the AI cannot manage more then one or two attacks at a time. This allows the player to win simply by hitting his enemy at a faster rate.
 * There's a glitch in the seventh Fire Emblem game that lets you control your enemies. By placing a mine on the ground, waiting for an enemy to step on it, and resetting the game while the HP bar decreases, you are able to move your enemies just like you would your own units. It's only for one turn, but that's enough for you to make everyone drop their weapons (or hand them to you) if you wish.
 * The "Uberspear" that gives major boosts to Vaida's stats when she appears as a boss is not a bug. Being able to steal it off of her and enjoy the stat boosts yourself is.
 * In FE8, that enemy control glitch (which can now be activated by normal combat damage as long as it's the enemy's turn) still lets you make all the enemies hand their weapons and equipment to your team. Including, say, claws, teeth, and eyes, which the game treats as weapons. And if you then equip eyes, you can train any character, no matter their class, in dark magic (which, if this editor understands correctly, will replace the normal weapon abilities of non-casters). You can also give rare items to a gorgon egg, which will mark its whole inventory except the first item as "items which will be dropped when I die", wait for it to hatch, and kill it, and when you do all the items will be fully recharged, even the unique items which were specifically designed to be unrechargable.
 * As well, you can recharge elixirs by letting an enemy thief steal one and then kill him.
 * Same thief trick also serves to recharge Myrrh's Dragonstone.
 * In FE4 there's a Bug that lets you put one of the Game Breaker Legendary Weapons into a shop, allowing a better statted character to buy it, and assumedly use it.
 * And while their status as "Glitches" or "Bugs" is highly debatable (As both are results of correctly working systems in the game), there's at least 2 tricks that allow your to pair The Hero Celice with his half-sister, and resident Mysterious Waif, Yuria. (First involves forming a particular square of units and not saving for 2 and a half chapters; the other involves having Celice wait next to a Brainwashed and Crazy Yuria on the final chapter).
 * And finally, there's a possiblity that even the plot itself can fall victim to a glitch, or exactly the unbridled WRATH of the Random Number God-- it's possible for Ethlin and Cuan to kill the Thracian Knights in Chapter 5.
 * In FE10, an enemy Bishop with a Rescue staff can place an enemy on top of a pitfall trap in Chapter 3-11. This allows a unit with Pass to move through the square unimpeded, as well as creating a very silly situation where a unit can engage an enemy and then fall into a pit as soon as they try to pass through the recently occupied space. More importantly, this suggests that by placing your own flying units atop one of these spaces, you can move your non-fliers past the pitfalls, since the game will not allow two units to occupy the same space and therefore will not stop them as they go over the pitfalls.
 * Final Fantasy Tactics. Ninja can attack twice. Knights can break equipment. Combining both (Knight+Two Swords or Ninja Break Tech) gives you two chances of breaking it in one turn. That's all intentional, but it seems the game only removes the 'Broken' item after the attack. So if the first strike breaks the target's weapon, there's still a chance that they somehow block the second strike.
 * In the PC port of Valkyria Chronicles the reaction attack speed of shocktroopers (SMG users) and tank machine guns was tied to the frame rate. This generally meant they had double power on defense. This actually worked in the game's favor balance wise, as it made defensive play more viable, increased the usefulness of a previously mediocre class, and discouraged "scout rush" strategies (running to the enemy's final base with a buffed up scout to win most maps in a turn or two) which were far and away the best way to beat most levels of the PS3 release. The bug was unfortunately fixed, but a mod exists to restore it.