Effects are the particle auras you strap onto your knife in Murder Mystery 2: flames, ghosts, hearts, gears, whatever fits your loadout. Some also change what happens to a victim, turning bodies into gears, pixels, or a burst of confetti. A small shelf of them sits in the shop for Coins or Diamonds, but most arrived through gamepass packs and years of event battle passes, which is why the roster reads like the game's event history.
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Showing 82 of 116 items.
Source
Shop
The permanent lineup, priced in Coins or Diamonds. A couple of early entries were retired over the years, but the rest can be bought whenever the mood strikes.
Blue Flaming Knife
Sets your blade alight with blue fire, the cool-toned sibling of the classic Flaming Knife. A straightforward Diamond buy from the shop.
- Availability
- Available
- Cost
- 800 Diamonds
Doge
Small Doge heads drift off the knife, and victims turn into a Doge on death. A meme relic that left the shop with the Season 1 update, so only older accounts carry it.
- Availability
- Available
- Cost
- 500 Coins
Dual Wield
Puts a mirrored second knife in your off hand. Pure style, since only the real knife lands hits, but no other effect changes your silhouette this much.
- Availability
- Available
- Cost
- 900 Diamonds
Electric Knife
Wraps the blade in a ring of purple electricity. One of the pricier Diamond effects and easy to spot from across a map.
- Availability
- Available
- Cost
- 1,000 Diamonds
Flaming Knife
The classic fire effect: your knife simply burns. Cheap for Coins and still one of the most recognizable looks in the game.
- Availability
- Available
- Cost
- 4,000 Coins
Ghostify
Turns the knife ghostly and translucent. One of the few effects sold for either Coins or Diamonds, so almost anyone can afford the spooky look.
- Availability
- Available
- Cost
- 2,000 Coins
Green Flaming Knife
Burns the blade in green fire, the toxic-looking recolor of Flaming Knife at the same Diamond price as its blue and pink siblings.
- Availability
- Available
- Cost
- 800 Diamonds
Heartify
The knife sheds pink hearts, and anyone you take down ends up with a smiling heart-eyed face. The romance option, permanently in the shop.
- Availability
- Available
- Cost
- 2,400 Coins
Knifeception
Your knife emits tiny copies of itself, a knife within a knife. The joke lands better the fancier the knife you pair it with.
- Availability
- Available
- Cost
- 300 Diamonds
Monify
Rained money particles off the blade before it quietly left the shop in 2016. One of the rarest shop effects simply because so few bought it in time.
- Availability
- Retired
- Cost
- 700 Coins
Musical
Music notes float off the knife and stabs play a musical sting. One of the few effects you can hear as well as see.
- Availability
- Available
- Cost
- 2,000 Coins
Pink Flaming Knife
Pink fire for the blade, the flashiest of the three colored flame recolors and the same Diamond price as the others.
- Availability
- Available
- Cost
- 800 Diamonds
Radioactive
Coats the knife in green smoky particles and tints victims green, a budget Coins pick that still reads clearly in a dark map.
- Availability
- Available
- Cost
- 1,600 Coins
Source
Gamepass and Bundle
Effects that shipped inside Robux item packs and bundles. Most packs are offsale now, so these effects quietly became badges of when their owners joined.
Bats
A swarm of little bats circles the blade constantly. A Halloween pack effect that pairs naturally with the season's knives.
- Availability
- Retired
- Cost
- 1,299 Robux
- Event
- Halloween Event
Bitsplosion
Confetti-like colored bits spray from the knife, and victims burst into rainbow pixels. One of the few effects whose icon shows no knife at all.
- Availability
- Retired
Blizzard
Icicle particles spin around the blade. It came in the Winter Item Pack for 1299 Robux during the 2017 Christmas Event and left when the pack did.
- Availability
- Retired
- Cost
- 1299 Robux
- Event
- Christmas Event
Darkfire
Engulfs the knife in black flame and burns victims with it. The Shadow Item Pack's signature effect and a longtime favorite for dark loadouts.
- Availability
- Retired
- Cost
- 1,299 Robux
Elite-ify
Dark elite skulls orbit the knife, and victims turn into black skeletons burning in red fire. One of the most aggressive death effects in the game.
- Availability
- Retired
Ethereal
Light blue smoke drifts off the blade. It shipped in the Ghostly Item Pack for 1,700 Robux during the 2019 Halloween Event.
- Availability
- Retired
- Cost
- 1,700 Robux
- Event
- Halloween Event
Frostbite
An icy aura from the Frostbite Pack of the 2019 Christmas Event, gone since the pack was removed when the event closed.
- Availability
- Retired
- Event
- Christmas Event
Gearstorm
Gears spray from the knife and victims collapse into a pile of gears. The Clockwork Item Pack's effect, now offsale.
- Availability
- Retired
Ghostly
A teal and light green ghostly flare wraps the blade, spookier in motion than it sounds on paper.
- Availability
- Retired
- Cost
- 3,399 Robux
- Event
- Halloween Event
Ice Magic
A blue and purple icy shimmer with light pink flecks flowing around the blade. One of the more delicate winter looks.
- Availability
- Retired
- Cost
- 3,399 Robux
- Event
- Christmas Event
Petals
A pink haze of falling sakura petals surrounds the blade, the go-to pick for cherry-blossom loadouts.
- Availability
- Retired
- Cost
- 3,399 Robux
- Event
- Valentines Event
Plasma
Purple and blue plasma arcs spark across the blade under a white glow. One of the most electric-looking effects available.
- Availability
- Retired
- Cost
- 3,399 Robux
Rainbow
Radiant rainbow flames pour off the knife. The loudest of the flame effects and impossible to mistake for anything else.
- Availability
- Retired
- Cost
- 3,399 Robux
- Event
- Easter Event
Vampire
A red smoky haze with blood particles seeps from the blade. It came in the Vampire Item Pack for 1,699 Robux during a Halloween event and left when the pack went offsale.
- Availability
- Retired
- Cost
- 1,699 Robux
- Event
- Halloween Event
Darkswirl
A black aura coils around the blade and pours out of victims when they fall. The gloomiest of the pack effects.
- Availability
- Retired
- Cost
- 3,399 Robux
- Event
- Halloween Event 2023
Flow
A flowing blue aura with pool-reflection light lines, and victims give off blue flames when downed. A clean look for water-themed knives.
- Availability
- Retired
- Cost
- 3,399 Robux
- Event
- Summer Event 2023
Aurora Lights
Blue and purple northern-light ribbons wrap the knife, and victims glow in the same aurora shades. A bundle effect built to match icy weapon skins.
- Availability
- Retired
- Cost
- 3,399 Robux
- Event
- Christmas Event 2024
Flowerwood
Blue smoke and cyan particles tuned to the Flowerwood Bundle's palette. Made to complete that bundle's matching look.
- Availability
- Retired
- Cost
- 3,399 Robux
- Event
- Easter Event 2024
Glisten
The blue and pink cousin of Sunbeams: the same beaming trail in cooler colors, with downed victims glowing in blue and pink sparkles.
- Availability
- Retired
- Event
- Summer Event 2024
Wraith
White and black smoke shrouds the weapon and trails behind you as you move, and victims vanish into thick white smoke.
- Availability
- Retired
- Cost
- 3,399 Robux
- Event
- Halloween Event 2024
Bloom
A pastel pink aura with falling flowers and drifting petals that trail behind you as you move. One of the softest looks in the effect pool.
- Availability
- Retired
- Cost
- 3,399 Robux
- Event
- Easter Event 2025
Snowstorm
A white and blue snowy aura with drifting flakes, and victims emit the same wintry swirl when downed.
- Availability
- Retired
- Cost
- 3,399 Robux
- Event
- Christmas Event 2025
Xeno
A purple electrical aura crackles around the knife, and downed victims emit purple lightning. The alien-tech look.
- Availability
- Retired
- Cost
- 3,399 Robux
- Event
- Halloween Event 2025
Ocean
Neon blue and cyan aura with sparkles and tiny starfish drifting around the knife. Came with the Summer Event 2026 Beach Bundle.
- Availability
- Retired
- Cost
- 3,399 Robux
- Event
- Summer Event 2026
Pixie Dust
Pink and light yellow sparkles dust the knife, and victims shimmer with the same particles. Bought with the Valentines Event 2026 Sweet Bundle.
- Availability
- Retired
- Cost
- 3,399 Robux
- Event
- Valentines Event 2026
Source
Event Battle Pass
Tier rewards from event battle passes across Halloween, Christmas, Easter, and Summer seasons. Each card names its event and year, and each stopped being earnable when its pass ended.
Poison
A dripping green haze seeps off the blade. A Halloween battle pass reward for players who like their knives toxic.
- Availability
- Event reward
- Event
- Halloween Event 2019
Frostfire
Cold-burning flames from tier 17 of the 2020 Christmas Event battle pass, an early example of the icy fire look.
- Availability
- Event reward
- Event
- Christmas Event 2020
Ghosts (2020)
White smog and faint mini ghosts drift off the blade. The 2020 Halloween battle pass entry that started the yearly ghost effect series.
- Availability
- Event reward
- Event
- Halloween Event 2020
Jingle
A red and green aura with sparkles rings the blade. A Christmas battle pass reward.
- Availability
- Event reward
- Event
- Christmas Event 2020
Snowfall
Small snowflakes fall gently around the blade. The subtle option among the winter battle pass effects.
- Availability
- Event reward
- Event
- Christmas Event 2020
Aurora
A pink and green aurora ripples around the knife. A Christmas battle pass reward for players who climbed the tiers.
- Availability
- Event reward
- Event
- Christmas Event 2021
Phantom
A smoky green ghoul haunts the knife. A Halloween battle pass reward with one of the most distinct silhouettes.
- Availability
- Event reward
- Event
- Halloween Event 2021
Snowflake
The knife shimmers white while snowflakes drift down. A Christmas battle pass reward, softer than the token-shop snowflake effects.
- Availability
- Event reward
- Event
- Christmas Event 2021
Starry
A yellow aura studded with stars wraps the knife. A battle pass reward that keeps things simple and bright.
- Availability
- Event reward
- Event
- Christmas Event 2021
Wraithfire
A smoky purple aura coils around the blade. A Halloween battle pass reward darker than most of its year.
- Availability
- Event reward
- Event
- Halloween Event 2021
Arctic
Dark and light blue mist swirls around the blade like arctic wind. Tier 18 of the Christmas Event 2022 battle pass.
- Availability
- Event reward
- Event
- Christmas Event 2022
Candies (2022)
Candies fade in and out around the blade in a steady loop. The 2022 Halloween battle pass take on the candy effect.
- Availability
- Event reward
- Event
- Halloween Event 2022
Chilly
Wispy white smoke curls off the blade like snow on the wind. A Christmas battle pass reward.
- Availability
- Event reward
- Event
- Christmas Event 2022
Minty
A red and white aura like a candy cane dissolved around the blade. A Christmas battle pass reward.
- Availability
- Event reward
- Event
- Christmas Event 2022
Pumpkin (2022)
A glowing orange aura with flickering jack-o-lantern faces. The 2022 Halloween battle pass pumpkin.
- Availability
- Event reward
- Event
- Halloween Event 2022
Stickers
Sticker versions of red and green baubles and peppermints ring the blade. A Christmas battle pass reward.
- Availability
- Event reward
- Event
- Christmas Event 2022
Toxic
A green aura with rising bubbles wraps the blade. A Halloween battle pass reward in classic hazard green.
- Availability
- Event reward
- Event
- Halloween Event 2022
Versus
Stickers of the Survivor and the Zombie King circle the knife, a souvenir of the event's two sides. A Halloween battle pass reward.
- Availability
- Event reward
- Event
- Halloween Event 2022
Candies (2023)
Differently colored candies orbit the knife on repeat. The 2023 Halloween battle pass version of the candy line.
- Availability
- Event reward
- Event
- Halloween Event 2023
Fireworks
Neon blue, red, green, and pink fireworks pop around the blade in varying shapes. A summer battle pass showstopper.
- Availability
- Event reward
- Event
- Christmas Event 2023
Ghosts (2023)
Small ghosts float out of the knife. The 2023 Halloween battle pass revision of the ghost line.
- Availability
- Event reward
- Event
- Halloween Event 2023
Glowy
Three glowing pumpkins in cyan, magenta, and yellow orbit the knife, cycling through nine colors. A Halloween battle pass standout.
- Availability
- Event reward
- Event
- Halloween Event 2023
Stars
A faint yellow aura with neon star outlines around the blade. Sits next to Starry in the night-sky family with a sharper look.
- Availability
- Event reward
- Event
- Christmas Event 2023
Swirls
Red-white and green-white peppermint swirls circle the knife. A Christmas battle pass reward that doubles as a candy shop ad.
- Availability
- Event reward
- Event
- Christmas Event 2023
Traveler's Flame
A flowing orange flame aura, and downed victims burn with orange flames from the head. A Halloween battle pass reward with an oddly specific death effect.
- Availability
- Event reward
- Event
- Halloween Event 2023
Celestial
A deep blue cloud with floating yellow dots and stars drifts around the knife. A battle pass reward for the space-minded.
- Availability
- Event reward
- Event
- Christmas Event 2024
Cursed
A fierce green flame-like aura built to match the Cursed Knife and Gun. A Halloween battle pass reward.
- Availability
- Event reward
- Event
- Halloween Event 2024
Flowers
A faint white aura with white daisies and petals. The quietest of the floral effects, from a spring battle pass.
- Availability
- Event reward
- Event
- Easter Event 2024
Ghosts (2024)
Ghostly white smog with mini ghosts and no death effect. The 2024 entry in the yearly ghost series.
- Availability
- Event reward
- Event
- Halloween Event 2024
Gifts
Red and green presents tumble off the blade with no death effect. A Christmas battle pass reward.
- Availability
- Event reward
- Event
- Christmas Event 2024
Snowy
A white cloudy aura sheds snowflakes around the blade with no death effect. A Christmas battle pass reward.
- Availability
- Event reward
- Event
- Christmas Event 2024
Vampiric
A red smoky aura gives the blade a gloomy blood-tinged look with no death effect. A Halloween battle pass reward.
- Availability
- Event reward
- Event
- Halloween Event 2024
Abduction
A pale green UFO glow wraps the blade, and victims rise inside green abduction rings. Tier 24 of the Halloween Event 2025 battle pass.
- Availability
- Event reward
- Event
- Halloween Event 2025
Aquatic
A bright blue watery aura washes over the knife, with a matching splash on downed victims. A summer battle pass reward.
- Availability
- Event reward
- Event
- Summer Event 2025
Cat Eyes
Black fog with glowing yellow cat eyes surrounds the blade, no death effect needed to be unsettling. A Halloween battle pass reward.
- Availability
- Event reward
- Event
- Halloween Event 2025
Confetti
Pink and white streamers burst from the knife with no death effect. The most celebratory thing you can stab someone with.
- Availability
- Event reward
- Event
- Christmas Event 2025
Flamingo
Flamingos and pink feathers circle the knife with no death effect. The summer battle pass at its least serious.
- Availability
- Event reward
- Event
- Summer Event 2025
Frost
A gloomy cold sparkle wraps the blade, and a cold aura glows out of victims when they fall. An icy pick that stays readable in dark maps.
- Availability
- Event reward
- Event
- Christmas Event 2025
Heatwave
A bold orange fiery aura that also washes victims in vibrant orange. A summer battle pass reward that lives up to its name.
- Availability
- Event reward
- Event
- Summer Event 2025
Retro
Funky neon shapes in green, red, yellow, and magenta bounce around the blade, and victims burst into the same shapes. A style statement from a summer battle pass.
- Availability
- Event reward
- Event
- Summer Event 2025
Snowballs
Sticker-style snowballs pop around the knife with no death effect. A playful Christmas battle pass reward.
- Availability
- Event reward
- Event
- Christmas Event 2025
Synthwave
A neon aura of angular blue and purple shapes, with victims dissolving into a bluish-purple abstract glow. The retrowave pick of the battle pass effects.
- Availability
- Event reward
- Event
- Summer Event 2025
Treats
Sticker-style candy wrappers, chocolate bars, gummy worms, and lollipops orbit the knife. A Halloween battle pass reward with no death effect.
- Availability
- Event reward
- Event
- Halloween Event 2025
UFOs
Little UFOs spawn and buzz around the blade with no death effect. A Halloween battle pass reward.
- Availability
- Event reward
- Event
- Halloween Event 2025
How effects work
An effect equips onto your knife and follows it everywhere: held, thrown, or dropped. Many carry a second half, the death effect, which plays on any player you take down. Effects are visual only, they change no damage or speed, and they are not tradable, so the only way to wear one is to have earned or bought it yourself.
One knife, one effect. Since the effect layers over whatever skin you carry, the usual move is picking an effect that matches your best knife's palette rather than the flashiest one in your inventory.
Where effects come from
The shop shelf is the buy-anytime set, priced in Coins or Diamonds. Gamepass and bundle effects came attached to Robux item packs, most of which are now offsale, so those effects age into rarities on their own. The two biggest groups are event rewards: battle pass tiers and event prize or quest unlocks from every Halloween, Christmas, Easter, Summer, and Valentine's season. Once an event closes, its effects stop being earnable, and because there is no trading, they are permanently tied to the accounts that played.
Picking an effect worth chasing
- For a first effect, the Coins-priced shop picks like Flaming Knife or Radioactive do the job for pocket change.
- Death effects are the real flex. Effects like Elite-ify, Bitsplosion, or Gearstorm announce a kill to the whole room, while plain auras only decorate the blade.
- Event effects are the collector lane. A year-stamped ghost or candy effect is proof of attendance that nobody can buy afterward.
- If you own a matching weapon line, its companion effect (Cursed with the Cursed Knife, Flowerwood with its bundle) completes the set better than any unrelated aura.
Effects crafted in the Christmas Event 2025 crafting tab, the first time effects came from crafting instead of shops or passes.
Effects earned outside the pass: event shop purchases with event currency, quest completions, minigame prizes, and unboxing milestones.
The outliers: effects redeemed through real-world merchandise or platform promotions rather than anything in the game itself.
FAQ
What do effects actually do in Murder Mystery 2?
They add a visual aura to your equipped knife, and many also add a death effect that plays on players you eliminate. They are purely cosmetic: no effect changes damage, speed, or gameplay.
Are MM2 effects tradable?
No. Effects sit outside the trading system entirely, so unlike knives and guns, an event effect cannot be bought from another player later. The account that earned it is the only one that will ever have it.
How do you equip an effect?
Open your inventory, pick the effect, and equip it. It applies to whatever knife you are holding, and you can wear one effect at a time.
Which effects can I still get right now?
The shop effects marked Available, bought with Coins or Diamonds. Everything marked Event reward or Retired came from a closed event, an offsale pack, or an ended promotion, and returns only if the game reruns the source.
What is the difference between a knife effect and a death effect?
The knife effect is the aura around your blade while you carry it. The death effect is what plays on a victim's body, like turning into gears with Gearstorm or rainbow bits with Bitsplosion. Some effects only have the aura half.
