It looks like we'll finally say goodbye to the slag element of Borderlands.
Slag will be replaced, so fans of the element can look forward to something new: radiation. Gearbox Software CEO Randy Pitchford has stated that radiation is the newest element available in Borderlands 3, which works in the same vein, but with a few key differences.
This purported radiation element increases the vulnerability of enemies exposed to it much like slag, but also adds a damage over time effect, which is similar to the corrrosion effect. However, this does not mean that the corrosion effect will be removed; radiation, it appears, was Gearbox's way of balancing slag, which often become a situational item due to how it was useless without another gun dealing damage besides it, forcing you to either become the 'slag guy' in your party or just outright slag-and-switch while gunning solo.
While the transition to radiation has been hailed for the most part, seeing as slag was mostly seen as tedious, there have been some who have expressed concern with its visibility. Radiation will most likely be seen as colored yellow-green, a difficult color to distinguish for some who are colorblind. In order to address this, Pitchford has stated that Borderlands 3 will feature a colorblind mode, amongst other accessibility options.
Pitchford was also asked if there will be more skin varieties for weapons in Borderlands 3 than in the previous Borderlands games. One of the game's trailers has already indirectly answered this, with one of its taglines saying "over one biliion guns". That did not stop Pitchford from answering, though, and he sounded off with a simple "yes" in terms of the variety of cosmetics.
Pitchford also elaborated on the Echo Device skins that come with the Borderlands 3 Deluxe Edition. It would seem that player characters in-game will be able to carry a physical device around and equipping Echo skins is going to impact the UI for all kinds of transactions within the game.
Expect more of this kind of information to drop as we near the game's release. Borderlands 3 is a timed Epic Games Store exclusive for the PC, and it will release on the Xbox One, PlayStation 4 and PC on September 13, 2019.