what is the star with a bar to fill in your inventory stats for ???

[Mattbaka]

in the updated 1.6

[stellar__stevie]

i've been thinking the same thing but it's not on the wiki yet and nobody on reddit seems to be talking about it so. no spoilers for us it seems lol we'll have to wait

[boredomincorporated]

Skill mastery I assume is what you're talking about. Once you get all your skills to 10 that bar starts progressing to unlock the next level of mastery.

[Megadodo]

Once every skill is at level 10, doing activities that grant skill xp go towards filling that bar. Each level you gain allows you to unlock a special mastery skill (that you can unlock in the special cave in the lower right area of the forest, near the sewer entrance)