Before the 20th century, variation in the shape of characters was ubiquitous, a dynamic which continued after the invention of
woodblock printing. For example, prior to the
Qin dynasty (221–206 BC) the character meaning 'bright' was written as either or —with either or on the left, with the
component on the right.
Li Si (), the
Chancellor of Qin, attempted to universalize the Qin
small seal script across China following
the wars that had politically unified the country for the first time. Li prescribed the form of the word for 'bright', but some scribes ignored this and continued to write the character as . However, the increased usage of was followed by proliferation of a third variant: , with on the left—likely derived as a contraction of . Ultimately, became the character's standard form. New variants also result from larger shifts in the writing system as a whole, such as the process of
libian and
liding that resulted in the
clerical script. According to the palaeographer Qiu Xigui, the broadest trend in the evolution of Chinese characters over their history has been simplification, both in graphical
shape (), the "external appearances of individual graphs", and in graphical
form (), "overall changes in the distinguishing features of graphic[al] shape and calligraphic style, [...] in most cases refer[ring] to rather obvious and rather substantial changes".
Libian often involved significant omissions, additions, or transmutations of the forms used by Qin small seal script, while
liding is the direct regularization and linearization of shapes to convert them into clerical forms while preserving their original structure. For example, the character for 'year' underwent
liding to the clerical script form , while the same character after undergoing
libian resulted in the orthodox form . Similarly,
libian and
liding created the two distinct characters and for 'tiger'. There are variants that arise through the use of different radicals to refer to specific definitions of a polysemous character. For instance, the character could mean either 'a type of hawk' or 'carve'. Variants using different radicals to specify thus developed: respectively , with a radical, and , with a radical. In rare cases, two characters in ancient Chinese with similar meanings were confused and conflated when their modern Chinese readings merged, for example, and , are both read as and mean 'famine', used interchangeably in the modern language, even though initially meant 'insufficient food to satiate' and meant 'famine' in
Old Chinese. The two characters formerly belonged to two different Old Chinese
rime groups ( and groups, respectively) which indicates they had different pronunciations in the past. A similar situation is responsible for the existence of variants of the particle 'in' which had the ancient form , now used as its simplified form. In each case above, variants were merged into single simplified forms. == Orthodoxy ==