This question already has an answer here:

In XCOM: Enemy Unknown missions get more difficult as I advance in the game - at least in absolute terms. I was wondering if the mission difficulty does or does not depends on

  • Elapsed time (ingame)
  • Plot progress
  • Research progress
  • other factors

Anyone has any insight into this?

marked as duplicate by Zommuter, Billy Mailman, Robotnik, shanodin, user28379 Aug 26 '13 at 17:58

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

  • 2
    Definitely not the plot, as I held off investigating the shard for a long time but enemies continued to get tougher. Research seems unlikely as it could easily unbalance the game if you happened to research too fast or too slow. Most likely either Elapsed time, or some kind of counter that goes up for each mission you undertake (and maybe those that you don't). There isn't really a good way to know for sure. – Elbyron Nov 16 '12 at 23:58
  • 1
    Probably very related: gaming.stackexchange.com/questions/87524/… - Alien progression is really the primary way that missions get more difficult. – agent86 Nov 17 '12 at 0:19
  • From my experience it is the "number" of aliens. i.e. a "very easy" only has 4-6 aliens, while a "very hard" has like 14+. I'm not 100% sure of the exact figures, so I posted this as a comment, not an answer. – Laurence Nov 17 '12 at 5:27
  • @TheShiftExchange I'm not so sure this question is about nominal difficulty, I think they're more interested in actual difficulty, as in when tougher aliens are introduced, when missions come to have larger numbers of aliens, etc. – Theodore Murdock Nov 19 '12 at 3:18
  • My first time getting deep into classic mode I was taking my time and every mission was getting really packed with very tough enemies. My next playthrough I rushed all the storyline stuff and breezed through it. it definitely feels like it is game time based and not related to story (with the small exception that the first encounter with a given species is story based). – Dolphin Nov 25 '12 at 7:36

I do not know the exact equation but I am currently gathering data on a normal play-through. I suspect according to my data so far that mission difficulty is strongly affected by the country's current panic level increased by the other countries panic levels on the same continent. I do not yet know if rewards increase the difficulty.

Small differences can be seen in missions under otherwise similar circumstances, for example the first abduction missions had every country at panic 1 and average continent panic at 1. Here I was given the option of an easy mission or a moderate mission, indicating some sort of random variable in the Difficulty calculation.

So far it seems that if an abduction awards a soldier then the mission will be more difficult than a similar mission under the same circumstances but it could also be random.


I think the game caluculates your difficulty level based on story progress and research progress. If you don't progress with the story ethereals will appear without getting the beacon. Same thing goes the other way. If you get really far with the story you get harder enemies too. Which one goes faster i dont really know. Certain enemies are bound to certain types of missions. e.g. The Crissalid appears after your first terror mission.


Difficult levels are determined by type of aliens and their numbers. 6 groups of Sectoids are considered "Very Difficult", while 1 group of Mutons and 3 groups of Sectoids is equally noted as "Very Difficult".

  • 1
    Well, he actually asked what makes the game ramp up the difficulty level as you progress, not what characterises a difficult or easy mission. – Sandokan Apr 12 '13 at 9:59

Not the answer you're looking for? Browse other questions tagged or ask your own question.