1. The basic strokes of Chinese characters originated from the regular script of Wang Xizhi, a calligrapher in the Jin Dynasty, which stipulated the basic strokes of "horizontal, vertical, left-off, point, grip, pick and fold". The shape of strokes was further standardized, and the number and order of strokes of each character were also fixed.
2. Chinese characters have changed for a long time from Oracle Bone Inscriptions to Dazhuan, Xiaozhuan and Lishu. After the popularization of official script in Han Dynasty, regular script in the Three Kingdoms period took shape at the end of Han Dynasty. Therefore, Wang Xianzhi and Wang Xizhi's father and son further improved the regular script on this basis, and created "Eight Methods of Harmony" and one of the basic strokes of regular script. Because regular script has a square font, simple strokes and easy recognition, it deeply influenced the printing of later generations and became one of the standard fonts for ancient printed books (Song Ti and imitation Song Ti were also the fonts for book printing after the Song Dynasty).
Yong Zi and Eight Methods:
There are two opinions about the origin of 1 and the eight-character method:
One is from Preface to Lanting and Nine Years of Yonghe. This is thanks to Wang Xizhi, and it is inevitable that it will be far-fetched. In 1960s, Guo Moruo initiated the Lanting Theory. Mr. Qi Gong's article "The Superstition of Lanting should be Destroyed" says: The eight laws of the ancient characters come from the preface of the Nine Years of Yonghe in Lanting, which is also not allowed.
Second, when it comes to the later Han Dynasty, the reason is that there are not many strokes of the word "Yong", but the brushwork is rich and representative, so it is designated as the eight methods of courage. According to the brushwork of the Forbidden Classics in Yutang in the Tang Dynasty, "Eight methods started from official script and were taught by Cui in the later Han Dynasty ... The eight styles used should be 10,000 characters ..." This passage explains the origin of the "Eight methods with permanent characters". The official script here refers to regular script, because before the Tang Dynasty, regular script was called official script, and official script was called eight points.