TFT Patch 17.4 dropped on May 26, 2026, and it is one of the bigger mid-set patches Riot has shipped for Set 17 Space Gods. Two systems that players have complained about since launch got meaningful reworks. Arbiter no longer gives you random inputs and outputs that have nothing to do with your board. Psionic items no longer lock you into an AP or AD path by accident. Corki takes another tap down. Zed casts a little slower. And two-cost reroll finally gets enough support to be worth trying again.

If you have been avoiding Arbiter because it felt like a lottery, or skipping Psionic because drawing the wrong item type ruined your game, this patch has direct answers. If you have been hard forcing Corki or riding Dark Star 6 every lobby, expect a rougher time.

Here is the full breakdown of what changed, who it helps, and how to adjust your game plan.

Arbiter Is Not Random Anymore. Here Is How It Works Now.

The biggest quality-of-life change in 17.4 is how Arbiter’s Input and Output system works. Before this patch, you could load into a game with a great Leona board and pull an economy-skewed Input paired with a magic-resistance Output that did nothing for your comp. It made the trait feel unreliable, and players stopped building around it.

Starting in 17.4, Arbiter gives you one Input from each of three fixed pools, and one Output from each of three fixed pools, every single game.

The three Input pools:

  • Consistent (something you can trigger every round): Every 4 seconds, or For Each Arbiter Star Level

  • Conditional (tied to how your Arbiter unit plays): When an Arbiter Attacks 3 Times, or When an Arbiter Spends 50 Mana

  • Economy (tied to your gold and rolls): For Each Interest You Earn, or If You Rerolled Last Turn

The three Output pools:

  • Offense: Gain Ability Power, or Gain Attack Speed

  • Defense: Gain Permanent Max HP, Gain a Shield, or Gain Armor and Magic Resist

  • Economy: Chance to Get Gold, or Chance to Get a Leona

That structure means if you plan to run a defensive Leona board, you are always getting a defensive Output. If you plan to lean toward LeBlanc with a Rageblade, your offensive Output will be there. You no longer need to pray.

Arbiter Also Lets You Stack Past 100 Percent Now

If you are running a Leona-chance Output and your stack goes over 100 percent, the overflow now rolls again. Push it to 200 percent in a long fight and you pull two Leonas from one combat. Going from Arbiter 2 to Arbiter 3 actually means something now.

Combat-start shields also last 8 seconds now, up from 4. That was the main reason the shield outputs felt bad before. Your tank was losing the shield before it could matter.

The Arbiter Emblem picks up a bonus too: Attack Speed goes from 20 percent to 30 percent.

Psionic Items Work on Every Carry Now

The second major rework targets Psionic items. The old system punished you for drawing an AP-focused item when your intended carry was AD, or the other way around. The dev team acknowledged this directly, and the fix is clean.

All offensive Psionic items now have stats and effects that work on both AP and AD champions. Here is what each one does now:

Drone Uplink: Replaces AP scaling with a flat 15 percent Damage Amplification. Master Yi can hold this. AP carries can hold this. It stops being a wasted slot.

Malware Matrix: Grants 10 percent Damage Amp, 15 percent Attack Speed, and 10 percent Omnivamp. Attack champions reduce enemy Armor by 2 per hit. Magic champions now reduce enemy Magic Resist by 2 instead. So Victor stacks MR shred and Master Yi stacks Armor shred, both from the same item.

Sympathetic Implant: Grants Damage Amp and Attack Speed. Magic champions get Mana Regen from the passive. Attack champions get bonus Attack Speed instead. Putting it on Pyke or Master Yi still gives real value, roughly a weaker Quicksilver.

Target-Lock Optics (reworked): Old effect was niche and only worked well on Pyke. New version gives AD, AP, and AS. When the holder damages each enemy for the first time in a fight, Attack champions gain 9 percent bonus AD per enemy hit, and Magic champions gain 7 percent AP. On a Pyke that hits 4 targets with his dash, that is 36 percent extra AD stacked in the opener.

The Biomatter Preserver tank item is not changing. Only the carry items got the rework.

Radiant versions mirror the same effects with slightly higher numbers, so the upgrade path is clean and predictable too.

Every Two and Three Cost That Got Buffed in 17.4

This patch’s underlying goal is making two and three-cost reroll worth playing. After the 17.3 one-cost nerfs, those cheaper reroll lines did not step up. These buffs are Riot’s correction.

Two Costs

Bel’Veth: Her 17.3 nerf is fully reverted. Spell Damage AD goes back to 20/30/45/77.

Zoe: Gets a meaningful three-star buff. Her SP damage AP moves to 73/110/180 from 68/102/153. This only hits the first time she tags a target in each direction, not her full AoE, so it is roughly a 10 to 12 percent real-world buff. Worth testing as a three-star reroll carry.

Gnar: Base Attack Speed goes from 0.7 to 0.75. His slow attack speed was making him feel inconsistent as an item holder in early game boards. This should smooth out his early combat patterns.

Gwen: Resists go from 45 to 50, and her three-star single target damage climbs to 410 AP from 380. She falls off a cliff after Stage 2 Space Groove in 17.3, and this is a push to make her viable as a three-star Rogue carry.

Three Costs

Aurora: Split damage AP rises to 400/600/960 from 370/555/890. She was propped up by Anima Squad and never found her own identity. This is a direct buff to give her a standalone reason to hold items.

Miss Fortune (Replicator): Spell damage buffed to 275/415/660 AD from 250/375/600. The Replicator version was flat-out worse than just playing Lulu in the same slot. Now it has a reason to exist again.

Ornn: Gets 100 more base Health, moving to 950. Because Ornn scales off the items he forges, a healthier Ornn opens up more Stage 2 item plays and makes him a more consistent early frontliner.

Viktor: Spell damage nudged to 190/290/500 from 185/275/475. Small, but combined with the Psionic item rework, he has more usable item paths now.

Lulu (Mountain): Her Mountain variant’s stun drops from 0.5 seconds to 0.25 seconds. It was chain-stunning targets in a way that outclassed every other Lulu variant by a wide margin.

The Nerfs: Corki, Zed, Fiora, and Dark Star 6

Corki

Still the most played four-cost in 17.3. Riot is not trying to kill him, just reduce his reliance on stacking AD and Deathblade as the only path to winning. Missile damage AD drops from 30/44 percent to 28/42 percent. His Meeple Rocket damage drops from 120/180 percent AD to 110/165 percent AD, so he is less locked into five Meeple as the only viable comp.

Zed

His mana is adjusted to 40/100 from 50/100. He was casting too fast and not giving enemies a window to react with items like Edge of Night. He still fires early, just not as instantly. The Clone Health nerf moves from 33/40 percent to 33/45 percent, which is actually a buff to the three-star clone. Watch for Riot to revisit this.

Fiora

This is the indirect Master Yi nerf. Master Yi as a comp leans heavily on Fiora to hold aggro and deal true damage. Her true damage drops from 40/60 to 37/56 AD. Small tap, but it reduces her ability to solo a tank and give Yi free time to stack up. Combined with the Psionic item rework giving Yi more item flexibility, Riot views this as a fair trade.

Dark Star

Six-piece Dark Star was the only reason to play the trait. Four-piece was already well-stated on paper but never felt worth it when six was this far ahead. The (6) bonus drops from 85 percent to 70 percent, and Mini Dark Hole HP scaling is reduced. Four Dark Star stays mostly the same.

Rogue Emblem

Was the strongest emblem in 17.3 by a clear margin. Omnivamp drops from 40 percent to 25 percent.

Traits That Got Quietly Improved

Challenger (3) and (4): Attack Speed at the middle breakpoints goes up. Nobody wanted to play more than two Challenger. This nudge makes three and four Challenger worth considering in comps like the Diana and Miss Fortune board.

N.O.V.A. (5): All three carry outputs got buffed. Aatrox damage ramps harder. Akali’s bleed hits more targets faster. Kindred’s Damage Amp doubles to 10 percent and her mark timer drops from 5 seconds to 4.5 seconds. Three-star Aatrox in five Nova is now something to actually try, especially with armor items.

Meeple Emblem: Swapped from mana regen to 50 Health plus 4 percent Damage Amp per Meep. You can now put this on tanks, fighters, or carries and it feels like a real item.

Space Groove (7): Bonus goes from 10 percent to 15 percent. The seven-piece payoff was not worth reaching for before.

Stargazer Huntress (5) and (7): The teamwide Attack Speed aura drops slightly to reduce splash value, but the Attack Speed for Stargazer units at the five and seven breakpoints jumps significantly, to 45 and 70 percent respectively. At seven Stargazer, the whole enemy team gets marked.

Fountain (5): The healing rate ticks up to 3 percent and the AD/AP scaling at five moves to 9 percent from 7 percent. Five Fountain was too weak for how hard you work to reach it.

Augment Changes Worth Knowing

Nerfed:

  • Shieldmaiden (Leona hero augment): Mana requirements go up, slowing down the early streak that made it one of the best augments in the game.

  • Gragas: Spell damage dropped around 10 percent across all stars. Players figured out the correct build path late in 17.3 and he shot up in high-ELO.

  • Reach for the Stars (Jax): AP ratios reduced slightly. He is less contested now, making the augment easier to hit.

  • Kahunahuna: Bonus true damage drops from 125 percent to 100 percent AD. The gap between normal combat augments and Kahunahuna in the right comp was too wide.

Buffed:

  • Booster Pack: Total gold value increases from 10 to 12.

  • One Two Three: Now gives 2 one-cost units instead of 1.

  • Heart of the Swarm: Now includes 2 Tiny Duplicators so one-cost reroll players have a backup plan when luck runs cold.

  • Luxury Subscription: Gold per trigger bumps from 5 to 7. Was one of the worst augments in the set.

  • Timestream: HP per reroll jumps from 2 to 7. A big quality-of-life fix for a time-breaker focused augment that was barely doing anything.

Removed from 2-1 offer pool:

  • Mason’s Will and Sunfire Board are no longer offered on 2-1. Both need units on the board to function, and 2-1 is too early for either to provide real value.

Artifact and Radiant Item Shifts

A handful of artifacts and radiant items were either traps in the current environment or just undervalued.

  • Radiant Dragon’s Claw: Percent Max Health jumps from 22 percent to 28 percent.

  • Radiant Guinsoo’s Rageblade: AS per second increases from 14 percent to 16 percent.

  • Blighting Jewel: MR reduction improves from 4 to 6 per stack.

  • Luden’s Tempest: AD/AP ratio goes from 55 percent to 60 percent.

  • Yasuo’s Bladework: Attack Speed nearly doubles, from 10 percent to 20 percent.

  • Ekko’s Patience: Was buffed to 45 percent Damage Amp but triggered a double-damage bug post-launch and was temporarily disabled.