Your degree programme will determine some of your module choices.
You must take the compulsory modules for your current year of study in your registered degree programme (and note that you cannot change your degree programme during your first year at St Andrews). The requirements can be found in the course catalogue. In first year, you will have between 20 and 120 compulsory credits if you are studying full-time (less if part-time day or evening), depending on your degree programme.
For some subjects the modules you take may depend on your previous qualifications. For example, many language courses have separate modules for complete beginners and for students with qualifications at Higher, A-level or equivalent.
The St Andrews degree structure is designed to be flexible. Most students have some amount of choice in the modules that they choose each year. As indicated above, you might choose to take a module simply because you are interested in the topic. Alternatively, it might be a compulsory module for some different degree programme that you are considering switching to in the future, or you might just choose a module because you need to gain additional credits.
If you have been admitted to a degree programme in a single subject, it is very strongly recommended that you choose modules in at least one other subject which could lead to a degree, so giving a second pathway to Honours. There are a few 1000-level modules which do not lead to degrees (for example music, linguistics and the interdisciplinary modules), so read the course catalogue carefully.
As long as you take the necessary compulsory modules, your optional modules don't have to be in subjects in the same Faculty as your registered degree programme (although students in Arts, Divinity and Science cannot take modules in Medicine).
See also: rules by degree.
