Dwarven script (alphabet family)

The Dwarven script is a family of alphabets that use roughly the same letters, albeit with different meanings, as it was used for a variety of languages. With the exception of the Stélhelm script - which was a full-on abugida where marking vowels is mandatory - the Dwarven scripts are all impure abjads, meaning that marking vowels is optional (albeit not in loanwords and onomatopoeia).

Old Dwarven
The Dwarven family of scripts began its life in the form of the Old Dwarven script. It was considered perfectly suitable for writing down the Old Dwarven language. The usage of consonantal markers for the nature of the consonant was mandatory - vowel markers were optional, and may not even have been invented until near the end of the language's lifespan (they were largerly nonexistent in earlier records, appearing more frequently much later).

Classical and Contemporary Dwarven
Even though the original Old Dwarven script was considered perfectly suitable for writing a version of the Classical Dwarven language that was purified of all loanwords, the old script was considered defficient to accurately represent the increased number of consonantal phonemes of the Classical Dwarven language: a new innovation was a group of markers for consonants that altered their manner of articulation. These markers, just like the vowel markers, were optional, but they were frequently used in loanwords and onomatopoeia, as well in texts intended for children learning how to write, and foreigners learning Dwarven - even though they are intended to absent from text for the fully literate, their ommission can cause ambiguities that force the reader to figure out the word's pronounciation and meaning from context. A new vowel sign was also added, to mark front rounded vowels in loanwords and onomatopoeia.

The same writing system has remained in use for the contemporary Koiné language, as well as all the dialects - largerly the only difference is, that there has been a vowel shift that isn't reflected in the orthography at all, and the mergers of some consonants rendered a few letters partially redoundant (they are still kept, as the language mandates etymological spellings for native words, leaving phonetic spellings for loanwords amd onomatopoeia).

Proto-Human and Old Etrandish
In the Human Kingdom of Steelhelm, a modified variant of the Old Dwarven script was adopted first for writing Proto-Human, then for writing Old Etrandish. The Old Dwarven script was highly defficient to write down both languages, so they had to get creative. Initially, several phonemes of Proto-Human were conflated, due to the constraints of the writing system. Thankfully, the invention of a new diacritic to mark fricatives made the script largerly phonemic for Proto-Human. In order to write Old Etrandish, which had an increased number of vowel phonemes, some innovations from the Classical Dwarven script were borrowed, but the updated script was still defective and incapable of truly phonemically representing all the phonemes of Old Etrandish.