You can find Star Wars Jedi: Survivor outfits littered across the entire game if you know where to look. Of course, you might want to prioritise finding more practical collectibles like Health Stims or perks before you turn your attention to Cal's appearance, but acquiring some cool clothes to jazz up your Jedi is also a worthwhile pursuit.
As well as complete outfits, you'll also find separate clothing items, such as jackets, shirts, and pants. There are also different materials to be found, which can then be applied to the different aspects of your wardrobe. If you really want to change Cal's appearance, you can also alter his hair and beard, but if you'd rather stick with clothes, here are the Star Wars Jedi: Survivor outfits we've found so far, as well as how to equip them.
