Difficulty (EU2012)

The choice of difficulty levels is the very first step take when you play an X-COM game, and it will heavily define how the game will operate by adjusting what resources you start with and most importantly what sort of handicap or advantage is given to the enemy forces.

Unique to an X-COM game, XCOM:Enemy Unknown allows you to change difficulty level as you play if you are finding the game too easy, or too hard.

Starting Funds

Difficulty	North America	South America	Europe	Africa	Asia
Easy	§465		§315		§315
Normal
Classic	§300		§190	§242
Impossible	§275				§165

Easy

• 150% of monthly funds income
• Base global panic starts at 0
• A free satellite from start
• Most alien activity only raises panic by 1 if left unchecked
• Aliens use the Easy/Normal AI package, and aren't as numerous.
• No more than 5 Aliens at a time may engage the player in tactical mission
• XCOM soldiers have +1 bonus HP, starting with 6 instead of 5
• Soldiers cost $10
• XCOM HQ starts 42 units of power.
• XCOM HQ starts with an Officer Training School.
• Sectoids have their health reduced by 1 compared to Normal
• Thin Man aliens' damage is reduced by 2, and their HP is reduced by 1 compared to Normal
• Aliens hesitate to use special abilities and throw grenades

Normal

• 100% of monthly funds income
• Base global panic starts at 0
• Most minor alien activity raises panic by 1 in left unchecked with some events doing up to 3
• No more than 5 Aliens at a time may engage the player in tactical mission
• Alien AI is limited (aliens can skip their turn, run away or take suboptimal moves for no reason)
• Soldiers have standard 5 hitpoints
• Soldiers cost $10
• XCOM HQ has 35 units of starting power.
• XCOM HQ starts with an Officer Training School.

Classic

• 100% of monthly funds income
• Base global panic starts at 8 (8 nations start with 2 panic, other 8 has 1.)
• Unchecked alien activity causes at least 1 panic, but will often cause 2 or 3
• Country with unchecked abduction gets 2 panic, other countries on that continent get 1 panic
• There are more alien packs per mission and bigger chance of a pack having more aliens (up to 3).
• Aliens receive bonuses: Chryssalids and Zombies recieve a +2 damage bonus, Muton berserkers receive a +1 damage bonus, all aliens that use ranged weapons receive a +10 Aim bonus, Mutons, Heavy Floaters, Drones, and Outsiders receive a +2 HP bonus, Sectoid Commanders and Cyberdiscs receive a +4 HP bonus, Sectoid Commanders and Ethereals receive a +25 Will bonus.
• Alien AI is unshackled (aliens can still run away in fear or put themselves in bad position sometimes due to AI not cheating and having to guess where your units are, but will never take an unoptimal move intentionally)
• Soldiers have -1 HP
• Soldiers cost $15
• XCOM HQ has 30 units of starting power
• XCOM HQ has no Office Training School at the start; a soldier must reach Sergeant to unlock the OTS base facility
• You do not start with an extra satellite
• Satellite coverage over continents such as scientists and engineers are smaller

. Eg. Full coverage over Europe grants 4 scientist on classic but on normal it grants 8 for full satellite coverage

Impossible

• 100% of monthly funds income
• Base global panic starts at 16 (all nations start with 2 panic)
• If unchecked alien activity causes at least 2 panic, but will often cause even more
• Country with unchecked abduction gets 3 panic, other countries on that continent get 1 panic
• There are even more aliens per mission and even bigger chance of a pack having more aliens (up to 3)
• Aliens receive bonuses: Many aliens do 2 to 4 bonus damage, all aliens using ranged weapons have +10 Aim except the Outsider and Muton Elite who receive +20 Aim, all aliens have +10 Critical Chance, Outsiders can move 5 more tiles per turn than in Easy, Normal, or Classic, Sectoid Commanders, Ethereals, and the Uber Ethereal receive bonus Will, with the first two getting +35 and the latter getting +10, many aliens receive +10 bonus Defense, and most aliens receive 1 to 5 bonus HP
• Compared to Classic, most notable change is +1 Health and +10 Aim of Sectoids, and +2 Health of Thin Men and Floaters, which provides for a huge difficulty increase on the first months of the game.
• Alien AI is unshackled (aliens can still run away in fear or put themselves in bad position sometimes due to AI not cheating and having to guess where your units are, but will never take an unoptimal move intendedly)
• Aliens use special abilities frequently, and are 40 times more likely to throw grenades compared to Easy and Normal
• Aliens are also not limited in terms of how many "heavy" units they can bring on the mission (like, 3 Sectopods at once is pretty common, unlike on Classic or lower)
• Soldiers have -2 hitpoints
• Soldiers cost $15
• XCOM HQ has 30 units of starting power.
• XCOM HQ starts without an Officer Training School; a soldier must reach Sergeant to unlock the OTS base facility
• You do not start with an extra satellite

Sub Options

In addition to the standard difficulty levels, the game offers two sub options that you can select before starting the game. Once set they cannot be switched off.

Tutorial Mode

Tutorial Mode puts you through a short series of guided missions and tasks done to teach you the basics of how to play the game. It also acts as a Prologue to the story, making it worth trying at least once even if you are already familiar with this game.

• This mode grants you one more satellite than you normally will start with if it is disabled
• Only 2 of the 5 starting continents are available in the Tutorial. They are otherwise available if you start without tutorial mode selected.
• This mode is disabled when starting the game on Impossible

Ironman

The Ironman game mode is a sub difficulty level that can be applied to any of the difficulty levels. This mode disallows you from saving the game manually and can not be disabled once the game has commenced.

• This makes the game more difficult since you cannot undo catastrophic mistakes or turns in combat.
• The game saves when:
  • You exit the game
  • Starting with turn 2 of combat, at the beginning of each player turn
  • When you enter mission control
  • When you leave any interface in base view (Mission Control, Situation Room, Research Labs, Engineering...)
• This mode can cause problems if you encounter bugs that cause non-progression, since you cannot go back to an earlier, hopefully more functional save state.
• Ironman can arguably 'save you from yourself' if you are the kind of player who would otherwise tend to reload any decision, combat, or turn that did not go well. While you are likely to do better as a result, overall gameplay may not be as fun as simply figuring out how to go on with the consequences.
• You can still easily "cheat" by making backups of the save files, or closing the game application after something unwanted happens but before your next turn begins in combat, however, this ruins the whole point of playing Ironman. These methods can also be considered a perfectly legal way to counter most of the bugs, however, including abilities doing nothing, enemies teleporting on your head, etc.

Ironman mode originates from an unofficial method of play that harkens back to the earlier X-COM titles where players wanting a challenge would self-impose a rule on their save/reload habits. This is traditionally done by manually disallowing the use of the save/reload facility to recover from mistakes, losses, and cheating. Regular saving is still encouraged to lock down progress or to avoid game bugs. This can still be done manually in XCOM Enemy Unknown, however the Ironman mode is provided to automate this process and is a requirement for certain Achievements.

Achievements

While not a difficulty per-se, the game offers a series of set achievements that you can earn by performing certain actions. These are either obtained automatically as you progress, or require you to perform task under difficult conditions such as winning the game on Classic/Imposible with Ironman enabled, or winning several full games from each of the starting base locations.

These goals do not offer any direct in-game benefits but can be collected at your leisure. For a full breakdown of the challenges, see: Achievements.

Miscellaneous information

• You can change difficulty level at any time during the game. It takes effect immediately, but not retroactively. For example, if you change difficulty level in combat from Classic to Impossible, enemies will immediately gain respective health and aim bonuses, however no new enemy packs would be spawned corresponding to the difficulty change.
  • (Unconfirmed information) This can also be used to avoid the rookie HP bug, if player so desires (the bug that makes new recruits arrive with standart 5 health even on harder difficulties). Changing difficulty right before the arrival of new soldiers will (reportedly) make them have correct amount of health.
• The games cheats for you on easy and normal difficulty.
  • On normal with 4 or fewer soldiers, or easy with precisely 4:
    • Chance to hit is 120% of displayed value
    • For hits that have at least a 50% chance of hitting, chance to hit is increased by 15% (absolute) per consecutive miss, with no upper limit
    • Alien chance to hit is reduced by 10% (absolute) for each consecutive hit.
  • On easy AND you are down to 3 or fewer soldiers:
    • Chance to hit is 120% of displayed value
    • Chance to hit is further increased by 15% (absolute) per missing squad member, under 4 (if you only brought 1 soldier, he has +45% chance to hit)
    • For hits that have at least a 50% chance of hitting, you receive another 15% (absolute) chance to hit per consecutive miss (up to 30%)
    • Alien chance to hit is reduced by 10% (absolute) for each consecutive hit.
    • Alien chance to hit is further reduced by 25% (absolute) for each squad member missing under 4