I can't understand: what's the difference between complicated and complex?


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  • In system theory: a system can be very complicated but not complex at all. Is system is complex when it has emergent behaviour. Complicated systems can be solved with enough computing power. Complex systems cannot be solved. thegreatcourses.com/courses/understanding-complexity.html – Patrick Savalle Mar 13 '15 at 23:51
  • Complex means a system which is elegant, reasonable and beautiful but takes time to learn and comprehend. Complicated means a system which is ugly and cobbled together without any explainable justification other than 'it seems to work'. – raindrop Dec 1 '18 at 16:29



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    This is not correct from a mathematical perspective. Complicated problems or systems are 'large' but still solvable or deterministic. Complex problems or systems have emergent properties and behaviour (such as self-organisation) that makes them non-deterministic / non-solvable, regardless the amount of computing power available. Very simple systems can also be complex. Very complicated systems don't need to be complex. These is a good primer on complexity. ncbi.nlm.nih.gov/pmc/articles/PMC2465602 – Patrick Savalle Mar 2 '17 at 12:20





Here endeth the pedantry.


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    I see. So, according to your pedantic explanation, the original verb meaning is implicit in the participle "complicated". A problem is complicated (adjective) because some external factor has complicated (verb) it. – Cameron Dec 8 '16 at 4:45
  • Hey @bye there is no chat system for stackexchange, but I just wanted to say I've read through a lot of your answers to different questions on the word usage in English and I think they're really great. Thanks for sharing! – zachaysan Mar 8 '18 at 15:25

In the Zen of Python, we have an aphorism

Simple is better than complex.
Complex is better than complicated.

It's a handy guideline when you are designing something.

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    So when programming python, you can divide up a task or problem into separate parts. The more parts, the more complex. Simple is better than complex, so don't add too many parts if you don't need them. On the other hand, if you want to do everything in one part, it might end up being too difficult, too complicated. Making it more complex (more parts) is better in that case. – Reinout van Rees Dec 21 '15 at 10:59


The instructions were way too complicated.






"Yes, but ... it's complicated."







complicated /ˈkɑmpləˌkeɪdɪd/
2. Medicine involving complications: complicated appendicitis.

adjective /ˌkɑmˈplɛks/



You can use them interchangeably.


1- The rules of the game seemed very complicated.



4- a complicated issue


1- The chemical processes involved are extremely complex.

2- the complex relationship between government and the media



To quote the salient bit:





Complicated is more used in social situations.


The usage of these terms is different, that's all.

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protected by RegDwigнt Jan 11 '12 at 15:28


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