It is not in the least easy.
If you are overseas chinese, there is a way to get ROC citizenship. Just follow their application process.
If you are a PRC citizen, you may only apply if you are married. But then there is a very long waiting list. This is the hardest path of all.
If you are a non-chinese woman and marry a man who is an ROC citzen, there is a way for you to become an ROC citizen. BUT, and this is a VERY big but, you must renounce your original citizenship.
If you are a non-chinese man, it is similar, but you must first be a resident for at least 6 months.
If you are not an overseas chinese and do not marry an ROC citizen, then it is not possible to get ROC citizenship.
Actually, it is better to just be a resident.
ROC citizenship is a very inconvenient citizenship since the ROC is not recognized by most countries. You need to get visa to go anywhere. Whatever your citizenship is now, you would be better off keeping it.
The ROC is not really a legitimate nation at all. It is the government in exile of China. But it does not hold the soveriegnty over the Taiwan territory. The ROC's role in Taiwan is as the occupier of the territory.The Taiwan territory is owned by the USA since it was ceded by the Japanese in the San Francisco Peace Treaty in 1951.Is it easy for a foreigner to be an ROC citizen?
No, It isnt.
Frankly before the year 2002 (I think) You could not be a Permanent Resident either. The ARC was the best for a Non -Chinese .
Foreigners of Chinese Ancestry (Not PRC Nationals) can still become full citizens of the ROC . They have a certain procedure for this-Dont know exactly what it is. Many of my Overseas Chinese Friends are ROC Nationals now.Is it easy for a foreigner to be an ROC citizen?
if you care to take a test (in traditional Mandarin) a few years after getting a permanent resident card. Then you can vote etc. I think.
You have to renounce your former citizenship. Thus I am not looking into it. Dual citizenship isn't happening here for people coming in from other places. (yet maybe that will change but now, nope.)
If your kids are born here they are citizens.