Open the Highschool Possession\game folder. (You can find where Highschool Possession is installed on your computer by right-clicking the title in your Steam client. Go to Properties -> Local Files -> Browse Local Files.)

If you're using the adult patch, install that first (since it replaces patch.rpy).

Open patch.rpy in a text editor. At the bottom, add the following lines (make sure to keep spacing and indents!):

Edit the font and/or size to whatever works for you.

To make the font smaller or larger, change the number after style.default.size =.

To change the font, place your desired font file in the game folder, then change style.default.font = "SourceSansPro-Semibold.ttf" to style.default.font = "YOUR_FONT_FILE_NAME".

For this example, I used verdana.ttf (which you can find under Control Panel -> Fonts) size 28. The result is a game with slightly larger and more readable font.

Because the game wasn't designed with a different font in mind, you may have some display issues, like menu text not fitting in the GUI. For example (using Verdana, size 24):



Also, long lines of text, especially with a very large font size, may break the text box. For example (using Verdana, size 36):

To change the font back to normal, simply remove the lines you added to patch.rpy.