I just had a dumb thought... languages based on Chinese characters must have written neologisms once in a while, right? And those neologisms must come with accompanying new characters too? Does this mean that, for example, science fiction or fantasy writers are allowed to come up with completely original new words like "chortle" or "grok" *and* also have new characters with which all readers would be unfamiliar at first?
How do languages written with ideograms acquire new ideograms?