How do runescribes activate the desired effect from ideographic runes with multiple, different meanings?

Question

There exists a radical offshoot of the Elder Futhark runic alphabet called kig-anr (“stone-symbols”) that evolved into an ideographic form consisting of over fifty different characters. People who use kig-anr to perform magic get referred as “runescribes” who do so through two means with tools that need to have magical energy channelled into them during useage: inscribing runes onto a solid surface with a sharp metal stylus which requires a lot of time and steady hand or custom-made wands called vǫndr to quickly project runes onto tangible objects by pointing at them.

Once manifested, the kig-anr runes take instant effect, burning out after they activate unless they have a klik-kig (“stop-symbol”) following them. A klik-kig serves as a punctuation marker of sorts indicating the end of a runic chain while syphoning life-force from living organisms (plants, animals or microbes) within a one-hundred-meter radius which becomes converted into energy used to fuel the runes’ effects. If the klik-kig gets destroyed through physical means, the runes will cease functioning and become nothing more than simple carvings.

However, each rune has multiple meanings attached to them and I'm clueless as to how a runescribe would invoke a desired effect from their chosen runes without the stupid, impractical idea of calling them out loud (something that you'd expect to find in shitty Shonen animu).

How can such a problem get solved?

Answer 1

“When I use a word,’ Humpty Dumpty said in rather a scornful tone, ‘it means just what I choose it to mean — neither more nor less.’

’The question is,’ said Alice, ‘whether you can make words mean so many different things.’

’The question is,’ said Humpty Dumpty, ‘which is to be master — that’s all.”$^1$

Like in common language a single word can have multiple meanings but the context in which that word is placed usually eliminates the ambiguity, so for this particular usage the context where the rune is placed self clarify which effect is desired.

Example with English, used as safe language since it doesn't have magic effects attached:

Rune: LEFT

• Usage 1: Turn LEFT alone (the target turns left)

• Usage 2: Be LEFT alone (the target is separated from its group)

$^1$ Source

Answer 2

In the language of the divine, each symbol has one and only one meaning.

Humans like the play fast and loose with words. The symbol for fire might come to mean "bright" (because fires are bright) or "burn" (because fires inflict burns) or "that feeling in the middle of autumn when you're sitting at a bonfire remembering how you used to do this as a kid", and then you check back in two hundred years and the last meaning has mutated into "reminisce" and nobody knows why. But that's only the word in human languages.

But in the divine language - the language of magic, or the gods, or the spirits, or whatever natural force is behind this phenomenon - the word has one and only one meaning. It will always mean fire, whether humans mean that or not. (Or even whether humans remember that it can mean fire or not...)

This may mean that expressing yourself precisely in the language of the divine is difficult or counterintuitive; magic often is. That's why you have dedicated runescribes rather than everyone's writing coming to life willy-nilly. It's why runescribes have to [do something that furthers your plot] rather than [do something else that completely ruins your plot], because it is difficult or impossible to precisely describe the latter in runes. It's why discovering a new rune, or one forgotten to time, is a huge deal (if you wish it to be).

Answer 3

How many runes are there and how many meaning per rune? EIther group runes together, or have enough of them to fomr a protolanguage of some sort, where the context makes grammar and disambiguates the meaning.

If there are only few meanings per rune, you can use diacritics to disambiguate.

In modern Pǔtōnghuà, you could, if you really want to, kind of get away with 800 runes and words of mostly two runes stuck together. In her predecessor Wényánwén you can have one rune = one meaning, however each rune is composed of a pronunciation part and the "core meaning" part, with about 200 of the latter (and you have many thousands of such runes).

Or use a special (determinative) runes to hint the meaning (as in Sumerian).

Eventually, if there are just few runes and many meaning depending on their combination, you will reinvent the alphabet.