What would a good gaming translation for 灵术 be?
Without knowing the full context, my best guess is that 灵术 means spirit magic.

When translating, especially between unrelated languages like English and Chinese, there is often a lack of one-to-one correspondence between words. This is why when you look in a dictionary for the English definition of 术, you get multiple options like technique/surgery. However, when this character is paired with others, it can also take on the meaning of magic. This works the other way around too; when you try to translate magic to Chinese, you get multiple options as well, like 魔术 (magic as in magicians) or 魔法 (magic as in Harry Potter).

You probably won't find "灵术" in a dictionary. Since your context is video games, it's most likely that this is a constructed word for a specific type of magic, which usually have the "X术" form. To demonstrate, here are some other "X术" words that are specific types of magic:


妖术, lit. "supernatural magic", often translated as "sorcery"
巫术, lit. "witch magic", translated as "witchcraft" or "black magic"
通灵术, lit. "communicate with spirits magic", sometimes translated as "necromancy". Note that "ouija board" in Chinese is 通灵板.
仙术, lit. "divine magic", translated as "theurgy"


Interestingly, there are many "X术" words that have nothing to do with magic, such as 医术 (medicine) and 武术 (martial arts). This goes back to traditional Chinese culture, especially Taoism where there is no clear distinction between the natural and supernatural, and that many physical phenomena also have supernatural links, like the concept of qi.