Murder Bridge is the collective term for several single-lane maps designed for the ARAM game mode. The original form was the tutorial map Proving Grounds, which was adapted into the Howling Abyss for the ARAM game mode, which was temporarily replaced by Butcher's Bridge during the Bilgewater: Burning Tides event in 2015.
- In matchmade games, players can reroll their randomly assigned champion using Reroll Credits. A player can have up to 2 Reroll Credits and Credits are unlocked by earning 250 ARAM points, which they will earn every time they finish a matchmade ARAM game (based on the number of champions that they own).
- If the game dodges, Reroll Credits will be refunded. This is unless you are the player that dodged the game.
- In matchmade games, players can purchase a Skin Boost during champion select for 95 that grants every player on their team a one-game only skin, chosen at random, for the champion that they're using that game. Additionally, the benefactor earns a 200 bonus from that game while their teammates get 100.
- If the game dodges, the RP is refunded.
- If a player rerolls or trades, they will receive a new skin at random. If you trade back for a champion you previously owned, you will receive the same skin as you did previously - trading cannot be used to reroll skins. (Tested, and confirmed)
- Howling Abyss
The Howling Abyss is a bottomless crevasse located in the coldest, cruelest, part of the Freljord. Legends say that, long ago, a great battle took place here on the narrow bridge spanning this chasm. No one remembers who fought here, or why, but it is said that if you listen carefully to the wind you can still hear the cries of the vanquished tossed howling into the Abyss.― In-client description.
- Butcher's Bridge
Butcher's Bridge is the massive dilapidated bridge looming above the slaughter-docks. Once an ancient stone bridge that led to a temple entrance, it's been kept up haphazardly and now makes the perfect battleground for an all-random fray.― In-client description.
- Proving Grounds
Proving Grounds Playable
A little over a month ago, a number of developers and I participated in Riot's first ever Thunderdome - a periodic, company-wide event aimed at allowing developers to work on whatever they want. My team set out to make the Proving Grounds, our basic tutorial map, playable as full on 5v5. This is something I've wanted to do ever since I originally worked on the map, and with the help of some other devs (and a good bit of caffeine) we managed to get everything up and running. Everyone was pretty happy with how the effort turned out, and with the upcoming removal of Winter Summoner's Rift we saw an opportunity to sneak the new map out by repurposing the same UI hooks.
In the next patch, the Proving Grounds map will be selectable in custom games. While we've been playtesting it internally as All Random (and lovin' it) for quite some time now, all the pick options will be available - Blind Pick, Draft, and All Random - because we're excited to see what variation you enjoy the most. We'd love to hear any feedback that you may have, as both RiotNome and myself will be providing support post release. Check it out and let us know what you think!
Additional information was released to the players on the forums:
Howling Abyss now on PBE!
It's been a while since I first talked to you guys about making ARAM an official gameplay mode, and today I've got something awesome to share with you. For the past few months I've been working with an exceptional team of artists to create a space that's an appropriate setting for both the epic battles that occur in ARAM and within the world of Runeterra at large. As a result, we've completely reworked the Proving Grounds and, in effect, created something entirely new.
Now, instead of fighting on a random bridge over a black void, you'll be fighting on the Howling Abyss, an ancient landmark in Freljord where the Iceborn finally overthrew their oppressors and sent them tumbling into the chasm below. As you might have guessed from these mysterious journals, there's more (a lot more!) our story team would love to tell you about Freljord - but for now, you'll have to wait.
Anyway, work is still ongoing on the map, and it's yet a few patches away from release but we just wanted to invite you guys in a bit earlier than normal to get your thoughts as we begin to polish it up. The environment team will be actively reading the forum and looking for your feedback, so please let us know what you think!
Additionally I wanted to let you guys know that we are actively working on an official matchmaking queue for ARAM and plan to launch it with the map when it's ready. The queue isn't currently enabled on PBE as there's still a good bit of tech work that needs to be resolved to handle the number of players on the environment, but we're fully committed to giving you guys the best experience that we can. So with that, check out the map and explore what we've created; who knows, maybe you'll even find some surprises!
New ARAM Feature: Rerolls
A few weeks ago, I let you know we were working on a matchmaking queue for Howling Abyss, but it wasn't quite ready for testing. Well, with today's PBE patch that's changed! Once PBE comes back up you can try out our new queue and help us test out a new ARAM feature we've added especially for this queue: rerolls.
While the random element is a really fun part of Howling Abyss, we also understand there are times you simply don't want to play a particular champion. That's why we created the reroll feature specifically for this queue. When you're really not in the mood to play your particular champion on Murder Bridge, you can reroll and get a different random character instead.
Here's how it works. As you play matchmade games on Howling Abyss, win or lose, you'll earn points you can save up to purchase a reroll in champion select. You'll earn a base number of points every match, along with some bonus points based on the number of champions you own. While there is a cap on the number of points you can store up, you'll be able to reroll multiple times in a single champion select if you've got the points.
And don't worry about wasting your hard-earned points on queue dodgers. If someone leaves your match at champion select, everyone in the game gets a refund except the player who dodged.
Building Butcher’s Bridge: the Bilgewater event
TLDR: Later this summer, we’ll launch our next event called Bilgewater: Burning Tides. As part of the event, the temporary Butcher’s Bridge ARAM map brings Bilgewater to life for the first time in game. Read on to learn more about the new map and the creative storm at Riot inspired by the possibilities in the teeming port city. 
Bilgewater: Burning Tides sails into port later this summer, but content from the event starts hitting PBE over the next few weeks. Consider this article a spoiler-free sneak peek, but you may want to avoid Bilgewater-related news until the event kicks off if you want to follow along with the story.
Bilgewater anchors the latest lore-inspired event after the Shadow Isles, the Freljord, and Shurima. Teams all over Riot felt it was pretty obvious the bustling port would make an awesome setting for an event for a while now. Narrative and world-building teams laid groundwork for an overlap of cultures and styles that’d scuff up the image of the place, and help the gritty black market come alive.
- WE'RE HEADING TO BILGEWATER
We ended up choosing Bilgewater when a dev team built a Bilgewater-style ARAM map from scratch during one of our Thunderdome hackathons. Everyone’s enthusiasm at seeing Bilgewater realized in-game drove the overarching thematic of the event. After the jolt of creativity sparked by Thunderdome, tons of teams across Riot banded together to deliver a Bilgewater experience with a wide swath of content--including a re-imagined evolution of that Thunderdome map.
- A NEW ARAM MAP
Butcher’s Bridge brings Bilgewater to life in game. In the new map, the original native culture of Bilgewater and the outside influence from across Runeterra meld together, showing off the stratified melting pot of races, cultures, and creeds.
We've incorporated blends of ancient and modern Bilgewater imagery on inhibitors, nexii, towers, and scattered around the bases. On one side, boat houses flank a temple door, and on the other side a giant ship hull sits ensconced, ringed by temple carvings on the sides of the cliffs. Rotating cannon turrets launch heavy artillery fire along with other small details designed to put you inside the pirate bay.
We're focusing on the visuals in this blog because the gameplay for ARAM isn’t changing at all; you’ll still experience the same frenetic all-random action. It’s just that now, given the nature of the slaughter-docks, you’ll be fighting on what is quite literally a murder bridge.
- TAKING ANOTHER LOOK
With the overall event goal to deliver an in-depth exploration of the world, we had to rethink exactly what it means to be a denizen of Bilgewater. Our explorations into the pirates, smugglers, and shanty-dwellers led us to an indigenous island society when it became clear the city had existed for centuries.
From those suggestions, artists evolved the architecture of the islands with vibrant colors, uniquely textured shapes, and decorative motifs. The native culture took on a bigger role in shaping the look of the environment, emphasizing the hunting and harvesting trade the indigenous peoples had made of sea monsters.
- SEA MONSTERS AND SEA-FARERS
The bustle and grind of a busy port betrays the wide variety of influences on the city. Between inverted Freljordian longships against the carved cliff-faces and the slow evolution of indigenous carvings and hints at other regions of the world, the depth in the narrative behind the streets and the culture finds new forms of expression.
- BUTCHER'S BRIDGE
As Runeterra’s biggest black market, keep your eyes peeled for clandestine, coded messages, illicit hextech pilfered from Piltover, and other easter eggs hidden amongst the shopkeepers’ wares and the assorted scattered items around the scene.
We're putting Butcher's Bridge through the wringer on PBE, and it’ll be moored up there just a little while since we still have some work left to make her seaworthy. One last note on the map: while Butcher’s Bridge is replacing Howling Abyss as your go-to destination for all-random assault during Bilgewater: Burning Tides, we’re still exploring post-event options.
Share your first impressions of the newest ARAM map and the upcoming event in the comments below or over on the boards. We’re excited to hear what you think, and can’t wait to join you for Bilgewater: Burning Tides, the next League of Legends event!
- The Howling Abyss location was the setting for a number of featured game modes:
- During the holidays of 2013, Riot's second featured game mode was called Snowdown.
- Between May 29 and June 8, 2014, Riot made a One for All: Mirror Mode available to play. Here everyone, friend and foe, fight each other as the same champion on this map.
- During the holidays of 2014, Riot released a game mode called Legend of the Poro King.
- In this mode each player has two poros following him.
- Spells are replaced by Poro Toss/Poro Dash and To the King!
- By tossing poros and tagging enemies 10 times, you summon The Poro King who has an area heal for teammates and area attack of poros for the enemies. By having him on the field, players that summoned him can easily dash to him.