Hi all is it possible to change font size (text size) in mission brief text or display text messages?

Yes. You have to edit the corresponding interface file (rez\*.bin for classic, rez\*.ui.json for remastered), changing the field's properties which include the font size. This way, for instance, I was able to fit more text into the mission objective box (rez\objctdlg.ui.json) - by finding the actual text box and removing the "RC_BIGTEXT" property from it.

The briefings are REZ\GluRdyP for Protoss, GluRdyT for Terran, GluRdyZ for Zerg; the extension depends on game version (see above).

In classic, the PyBIN or the older ShadowFlare's utility should help, and it's kinda WYSIWYG there. Double click the field in the list after loading up the .bin file and look for the Font box in the second row, check one of the boxes to specify the font (you cannot really specify the size in pts, just choose out of four (?) sizes. I think the field you need is the second from top, labelled "<10><10>No briefing data". You can click Font -> Size 10 to change the size to the smaller font (even though as I'm checking it now, the label isn't getting smaller for some reason).

In Remastered, it's all more straightforward as the .UI.JSON files are plain text. The syntax is a little convoluted (at least to me), however I'm unsure which of the text fields is the one you need. There are a few with "placeholder" content so you may need to experiment; I guess the "gluRdyT-9" is the one (if we take the Terran briefing), but it already has the "RC_SMALLTEXT" flag, so I'm not sure it can be made any smaller???

It's not possible with mapping tools. Do you want to do it in a mod?

Sorry i meant the the mission objectives not the mission brief before gameplay starts. i need to change fonts in mission objectives the box you can open while inside the gameplay. Maybe its still possible in one folder, but to understand your method correct: If i change some text code for font in my starcraft remastered files it will only change font size for me when im playing? or everyone that join my hosted map? or for this specific map? Cause i need the font size to be changed connected to the map as i cant tell all who wanna play the map to change their starcraft remastered files. Ill problaly better be off knowing its not possible with mapping tools

I dont need it for a mod thanks NudeRAider

Right, so within the map it should be considered impossible.

Sometimes people choose a wrong forum to post, or simply the issue turns out to be spanning several different categories (which is the case here, I think).

Its only good for mappers who need what you explainened they can search this site to find your answer. im not sure i can use it but others could. thanks for taking your time to answer this IlyaSnopchenko. sorry if i didnt explain my needs of help to the fulliest.