When Borderlands 4 gameplay was first shown off, one of the more curious reveals was the return (rather than replacement) of Radiation. The element first appeared in Borderlands 3, but never fully reached the iconic status of Borderlands 2’s fifth element, Slag, in part because no Vault Hunter was built to harness it fully. Following the reveal of Harlowe’s new skill trees, however, it seems that Borderlands 4 intends to give the element another opportunity to shine.
Replacing explosives in Borderlands' element rotation, Radiation spread damage between enemies and punished clustered groups, but the lack of visual impact left it feeling no more special than the other elements. Harlowe’s kit breathes new life into the status effect, finally giving it the focus it needed it lacked in Borderlands 3. Through Harlowe's Creative Bursts skill tree, Radiation becomes a core part of her damage identity, offering both passive boosts and active effects that could elevate the element into the spotlight.
Borderlands 4’s Harlowe Redefines Radiation Through Chain Reaction Chaos
Borderlands 3's Radiation was best used to chain damage from one enemy to another. When a target died while irradiated, it exploded into a damaging nova with the chance to spread the effect further. A subtle feature that added character to the element, it could also contaminate pools of water to create temporary spots of AoE damage.
As such, Radiation was best utilized to clear out clustered mobs. The element had a clear thematic identity, but without a dedicated playstyle to enhance it, the effect simply didn’t scale as effectively as other elements. Harlowe’s skills in Borderlands 4 bridge that gap through certain active abilities and passive upgrades, each focused on multiplying potential opportunities for chain reactions.
Harlowe’s CHROMA Accelerator Means More Explosions, More Often
The key to her Radiation synergy lies in Harlowe's CHROMA Accelerator Action Skill. The skill allows Harlowe to fire an Unstable Energy Pocket that inflicts Cryo damage as it passes near enemies, but the kicker is that activating the skill again triggers a massive detonation that deals heavy Radiation damage across a wide area. This creates immediate synergy with her passive trait, Entanglement, which links enemies affected by her Action Skills for extra gun damage, making Harlowe potentially one of Borderlands 4's best Vault Hunters.
By introducing passives that expand how she can irradiate targets, the middle branch of Harlowe's Creative Bursts skill tree could enable a devastating endgame Radiation build. The Fissile Launcher passive causes Radiation darts to be shot at another enemy when Harlowe damages an irradiated or entangled enemy, while the Dirty Bomb skill causes enemies to explode whenever hit with the status effect. The capstone skill, Demon Core, continues to stack on the damage by allowing her Unstable Energy Pocket to pepper foes with even more irradiated darts, for even more elemental explosions.
The Special Purpose Magnets Augment also allows Harlowe's Unstable Energy Pocket to pull enemies along, while also dealing increased damage to every enemy it has already hit when detonated.
Big Damage and Skill Versatility Mean Harlowe Could Be Borderlands 4’s Best Vault Hunter
What makes her an even more exciting Vault Hunter is that Radiation synergy is only one part of one of Harlowe's three Action Skills. Zero-Point, another of Harlowe's abilities, uses Stasis to entangle and lock down enemies or smash them into the ground. Meanwhile, Flux Generator is a deployable Cryo-damage field that buffs allies while also entangling nearby foes.
These alternate Action Skills suggest that, despite a dizzying damage potential, Harlowe can flex to also provide both area control and team utility, depending on which skill tree players invest in. This versatility could make Harlowe the most flexible Vault Hunter in the Borderlands franchise. Should that design philosophy extend to each of Borderlands 4 Vault Hunters, the game could set a new standard for endgame build diversity.
The synergy of crowd control and constant passive explosions makes Harlowe's CHROMA Accelerator the most appealing choice for exploring the possible endgame of Borderlands 4 so far, however. Whether or not it will rival the most dominant elemental builds of past games remains to be seen, but for the first time since its introduction, Radiation has a dedicated champion to showcase its destructive flair. If the tree is actually as powerful as it looks, Borderlands 4 could revitalize one of the franchise’s most underutilized elements.
Borderlands 4
-
OpenCritic Reviews
- Top Critic Avg: 82 /100 Critics Rec: 88%
- Released
- September 12, 2025
- ESRB
- Mature 17+ / Blood and Gore, Intense Violence, Sexual Themes, Strong Language, In-Game Purchases, Users Interact
- Developer(s)
- Gearbox Software
- Publisher(s)
- 2K
WHERE TO PLAY
- Engine
- Unreal Engine 5
- Multiplayer
- Online Co-Op, Online Multiplayer
- Cross-Platform Play
- Yes - all platforms
- Prequel(s)
- Borderlands 3, Borderlands 2, Borderlands
- Franchise
- Borderlands
- Number of Players
- 1-4 players
- Steam Deck Compatibility
- Unsupported
- PC Release Date
- September 12, 2025
- Xbox Series X|S Release Date
- September 12, 2025
- PS5 Release Date
- September 12, 2025
- Nintendo Switch 2 Release Date
- October 3, 2025
- Platform(s)
- PlayStation 5, Xbox Series X, Xbox Series S, Nintendo Switch 2, PC
- Local Co-Op Support
- Yes
- X|S Optimized
- Yes
