Often a character not commonly used (a "rare" or "variant" character) will appear in a personal or place name in Chinese, Japanese, Korean, and Vietnamese (see Chinese name, Japanese name, Korean name, and Vietnamese name, respectively). This has caused problems as many computer encoding systems include only the most common characters and exclude the less oft-used characters. This is especially a problem for personal names which often contain rare or classical, antiquated characters.

One man who has encountered this problem is Taiwanese politician Yu Shyi-kun (游錫堃, pinyin Yóu Xíkūn), due to the rarity of the last character in his name. Newspapers have dealt with this problem in varying ways, including using software to combine two existing, similar characters, including a picture of the personality, or, especially as is the case with Yu Shyi-kun, simply substituting a homophone for the rare character in the hope that the reader would be able to make the correct inference. Taiwanese political posters, movie posters etc. will often add the bopomofo phonetic symbols next to such a character. Japanese newspapers may render such names and words in katakana instead of kanji, and it is accepted practice for people to write names for which they are unsure of the correct kanji in katakana instead.

There are also some extremely complex characters which have understandably become rather rare. According to Joël Bellassen (1989), the most complex Chinese character is /𪚥 (U+2A6A5) zhé  listen (help·info), meaning "verbose" and boasting sixty-four strokes; this character fell from use around the 5th century. It might be argued, however, that while boasting the most strokes, it is not necessarily the most complex character (in terms of difficulty), as it simply requires writing the same sixteen-stroke character 龍 lóng (lit. "dragon") four times in the space for one. Another 64-stroke character is /𠔻 (U+2053B) zhèng composed of 興 xīng/xìng (lit. "flourish") four times.

One of the most complex characters found in modern Chinese dictionaries is 齉 (U+9F49) nàng  listen (help·info) (pictured below, middle image), meaning "snuffle" (that is, a pronunciation marred by a blocked nose), with "just" thirty-six strokes. However, this is not in common use. The most complex character that can be input using the Microsoft New Phonetic IME 2002a for Traditional Chinese is 龘 tà "the appearance of a dragon walking"; it is composed of the dragon radical represented three times, for a total of 16 × 3 = 48 strokes. Among the most complex characters in modern dictionaries and also in frequent modern use are 籲 yù "to implore", with 32 strokes; 鬱 yù: "luxuriant, lush; gloomy", with 29 strokes, as in 憂鬱 yōuyù "depressed", with 15 and 29 strokes, respectively; 豔 yàn "colorful", with 28 strokes; and 釁 xìn "quarrel", with 25 strokes, as in 挑釁 tiǎoxìn "to pick a fight". Also in occasional modern use is 鱻 xiān “fresh” (variant of 鮮 xiān) with 33 strokes.

In Japanese, an 84-stroke kokuji exists—it is composed of three "cloud" (雲) characters on top of the abovementioned triple "dragon" character (龘). Also meaning "the appearance of a dragon in flight", it has been pronounced おとど otodo, たいと taito, and だいと daito.

The most complex Chinese character still in use may be biáng (pictured right, bottom), with 57 strokes, which refers to Biang biang noodles, a type of noodle from China's Shaanxi province. This character along with syllable biang cannot be found in dictionaries. The fact that it represents a syllable that does not exist in any Standard Mandarin word means that it could be classified as a dialectal character.

Zhé, "verbose"

Zhèng "flourish"

Nàng, "poor enunciation due to snuffle"

Taito, "the appearance of a dragon in flight"

Biáng, a kind of noodle in Shaanxi