I have a game where players talk with characters with dialogue boxes. I would like each character to have their own font to add personality to the characters and dialogue. Will this create a legibility issue I'm not aware of? Do users have to reorient their reading each time they encounter a new font, or will this be fine as long as the fonts themselves are legible. Are there any other considerations for attempting something like this? Thanks in advance.
I don't think it's a legibility issue but a visual perception problem.
In general, people do not immediately perceive minor formal changes when the content has a bigger perceptual weight.
Making a price catalog for a company, with total freedom in design, from one year to the next I made a general typography change. There are about 250 pages of articles with names, text, description, references and prices. The screenshot below is the before and after comparison:
No one in the entire company noticed the change!
This case is a static object, a printed book with articles and prices. In the case of a game the situation is worse.
If the goal in the graphic development of the game is to achieve a greater emphasis on the personality of each character and the typographic change in the dialog box is the possibility, there are several factors to analyze:
Dialogue frame sizeIn small reading areas the change is hardly noticeable
Duration timeHow long each dialog text stays on screen, the shorter the time, the less chance to see the difference
Quantity of charactersFor just ten characters, a group of visually well differentiated fonts can be created. If they exceed this number it is much more complicated.
Dialogue extensionIn cases of lengthy dialogue in one character, a sudden font change when moving to another character will be perceived more as an error than as a character change.
Font Formal differencesWhat's the type of formal difference between the chosen fonts? The typographic visual variables are six: family, weight, inclination, size, proportion and color. In the question only a family change is mentioned, but in comics other variables are used to define emphasis in the dialogue, for example the variable of weight (bold) and inclination is used for words of greater interest:
What to highlightObject or content? The most important data to highlight is the personality of the character or the dialogue content?
Where to highlightIn my opinion, the most important point to consider: the change must definitely be in the font family or are there other possible elements to highlight as text color, underline, container frame, addition of icons, etc.?
I think the use of different typefaces within a game's dialog is so visually subtle that it does not compensate for the effort in exchange for the result obtained.
I recommend this link where is described in detail the grammar in comics to get ideas.