I sat this exam yesterday.
It was a fairly straightforward process that took about 30mins from start to finish.
On arriving, you say hi to the friendly staff who you probably know by name at this point in the process and hand over: your ARC, a 2"x2" passport photo, and 500NT. You’ll be asked whether you want to do the written or oral test and need to wait several minutes for some photocopying and test preparation.
The written test paper is A4 with two sides. The bulk of the first page is a table with three columns - the leftmost for your answers (you write in a ‘1’, ‘2’, ‘3’ or ‘4’), the middle column has the question and potential answer choices and the right column is used for grading. There are 20 questions, all of which appear in the question bank linked on the HHRO website. The final question may wrap around to the second page. The second page also has some notices, but they can be ignored (just explaining the score thresholds for passing).
One thing to be careful of is, unlike the question bank or the online practice test, answer choices are not laid out on their own line - it’s all one big paragraph without much in the way of formatting. Also, as others have noted, during the test you will be photographed, so don’t be alarmed.
On completion, you’ll be given a certificate with your details and score. If you complete the test at the same HHRO you are applying for naturalisation, they can add the certificate to your file so it’s one less document to verify on the day of your application.
In terms of studying for the test, don’t be daunted. I think it’s passable even with a ~60% comprehension of the characters in the questions. Personally, I studied gradually over a longer period, with a big push over the new year break. I went through a time where the language of the questions was just impenetrable, followed by a phase where the quirks of TW law were finally starting to make sense (Labor Pension Pay-in? 25 years - 65 years!). By the end of it, you’ve seen the questions so many times often the first few characters are enough to know what the answers are.
Oh, and, at time of writing, there are two related questions that have a different answer between the Taipei City online test and the question bank document from HHRO. Q 104 and 105 relate to how many years of mandatory schooling there are in Taiwan. Official doc says 9 years (i.e. 6-15yo), Taipei city site is 12 years (6-18yo). By the time you do the test, it may be the latter since that is the government policy objective. HHRO staffer said to defer to the official question bank document from the HHRO website.
HTH
You don’t need to do the test.
I suspect this was done on purpose (perhaps) after they became aware of the first crack guide.
