Just as Roman letters have a characteristic shape (lower-case letters mostly occupying the x-height, with ascenders or descenders on some letters), Chinese characters occupy a more or less square area in which the components of every character are written to fit in order to maintain a uniform size and shape, especially with small printed characters in Ming and sans-serif styles. Because of this, beginners often practise writing on squared graph paper, and the Chinese sometimes use the term "Square-Block Characters" (方块字 / 方塊字; fāngkuàizì), sometimes translated as tetragraph, in reference to Chinese characters.

Despite standardization, some nonstandard forms are commonly used, especially in handwriting.

Regional standards

The nature of Chinese characters makes it very easy to produce allographs for many characters, and there have been many efforts at orthographical standardization throughout history. In recent times, the widespread usage of the characters in several different nations has prevented any particular system becoming universally adopted and the standard form of many Chinese characters thus varies in different regions.

Mainland China adopted simplified characters in 1956, but Traditional Chinese characters are still used in Hong Kong, Macau and Taiwan. Singapore has also adopted Simplified Chinese characters. Postwar Japan has used its own less drastically simplified characters, Shinjitai, since 1946, while South Korea has limited its use of Chinese characters, and Vietnam andNorth Korea have completely abolished their use in favour of romanized Vietnamese and Hangul, respectively.

The standard character forms of each region are described in:

• The List of Frequently Used Characters in Modern Chinese for Mainland China.
• The List of Forms of Frequently Used Characters for Hong Kong.
• The Standard Form of National Characters for Taiwan.
• The list of Jōyō kanji for Japan.
• The Kangxi Dictionary (de facto) for Korea.

In addition to strictness in character size and shape, Chinese characters are written with very precise rules. The most important rules regard the strokes employed, stroke placement, and stroke order. Just as each region that uses Chinese characters has standardized character forms, each also has standardized stroke orders, with each standard being different. Most characters can be written with just one correct stroke order, though some words also have many valid stroke orders, which may occasionally result in different stroke counts. Some characters are also written with different stroke orders due to character simplification.