Dopplers are a skin, restricted to only knives, originally introduced to the game with the release of the Chroma Cases, and later from the Spectrum and Prisma Cases. The Gamma Dopplers were originally introduced with the release of the Gamma Cases, and later from the Operation Riptide and Dreams & Nightmares Cases.

Essentially, Doppler is a marbelized pattern which comes in different forms, some have a lower drop-rate than others, which makes some rarer than others.

As you may know, knives come in grades too, just like you see when you open cases (Blue, Purple, Pink, Red). For instance, Safari Mesh, Boreal Forest and Urban Masked knives would be the Milspec or "Blue" rarity for knives.

The Knife Grades are as Follows:
Rare (Blue) - No Doppler
Mythical (Purple) - Gamma and Chroma Phases 1-4 (2 sets of 4)
Legendary (Pink) - Ruby, Sapphire & Emerald
Ancient (Red) - Black Pearl

When unboxing a Doppler, there is a less than 10% chance that you will get a Legendary graded doppler (Sapphire, Ruby, Emerald). Unboxing an Ancient graded doppler (Black Pearl only) is estimated to be of around a 1% chance of getting if unboxing a doppler. As a result of this, Ancient and Legendary graded dopplers are much more expensive and rare.

To obtain Dopplers, you can either obviously trade for them, purchase them off of the Steam market or third party CSGO marketplaces (e.g. Skinport; buff163) or through the opening of designated cases as outlined below. (don't do this or you're going to lose all your money, trust me I know)

The Chroma Series (Chroma Case 1, 2, 3) are cases that released quite a long time ago, and was the case that first introduced the Doppler skins to the original set of knives, exclusive to those cases - similar to how the Fade skin is exclusive to other cases and will not drop from Chroma, Spectrum, Gamma, Prisma or Riptide knife collections.



As mentioned you can obtain Dopplers from the Chroma series:

the Spectrum series:

and the Prisma series:


while you can obtain Gamma Dopplers from the Gamma series:

and the Operation Riptide and Dreams & Nightmares series:

As you can see, by opening the Chroma, Spectrum, and Prisma series cases, you have an opportunity to obtain the original Doppler knives, Chroma Phase 1-4, Ruby & Sapphire and Black Pearl.

Similarly, by opening those cases with Gamma Dopplers, you have an opportunity to obtain the newer "Gamma Doppler" knives including Gamma Phase 1-4 and Emerald.

There are 12 main different variations of the Doppler, these are the Mythical variations of the skin:
Note: "Chroma" in this context refers to any original Dopplers, which were first introduced in the Chroma case but are not exclusive to it. Likewise, "Gamma" refers to any attainable Gamma Dopplers.

• Chroma Phase 1 - This variation consists of approximately 80% Black and 20% Red (1)
  
  
• Chroma Phase 2 - This variation consists of approximately 80% Red and 20% Black (3)
  
  
• Chroma Phase 3 - This variation consists of approximately 60% Blue, 10% Green and 20% Black (2)
  
  
• Chroma Phase 4 - This variation consists of approximately 80% Blue and 20% Black (4)
  
  
• Gamma Phase 1 - This variation consists of approximately 80% Black and 20% Green (1)
  
  
• Gamma Phase 2 - This variation consists of approximately 80% Green and 20% Black (3)
  
  
• Gamma Phase 3 - This variation consists of approximately 40% Green, 30% Black and 30% Aqua/Turquoise (2)
  
  
• Gamma Phase 4 - This variation consists of approximately 1/3 Green, 1/3 Black and 1/3 Lime Green (usually set out in a fade pattern) (4)

The Phase's are the most common variables of the Doppler, and are ranked from 1-4 in terms of their desirability. 1 being the least desirable (e.g. Chroma Phase 3) and 4 being the most. (e.g. Chroma Phase 4)


Chroma Phase 1 Picture (Karambit):

Source(s): My Old Inventory

Chroma Phase 2 Picture (Bayonet):
Source(s): The Steam Community Market

Chroma Phase 3 Picture (M9 Bayonet):
Source(s): opskins (shut down as of 2020)

Chroma Phase 4 Picture (Karambit):
Source(s): My Very Old Inventory, rip :(

Gamma Phase 1 Picture (Karambit):

Source(s): opskins (shut down as of 2020)

Gamma Phase 2 Picture (Karambit):

Source(s): opskins (shut down as of 2020)

Gamma Phase 3 Picture (M9 Bayonet):

Source(s): opskins (shut down as of 2020)

Gamma Phase 4 Picture (Karambit):

Source(s): opskins (shut down as of 2020)





Post March 2017 Update of CSGO: You can now obtain "Doppler" for remaining knives that did not have it before. e.g. Butterfly Knife, Shadow Daggers, etc.

These are the Legendary variations of the skin:

• Ruby - This variation consists of 100% marbelized bright Ruby. It is a very desirable skin and is quite rare in the doppler stance as you are more likely to get a Phase 1-4 variation. This version of doppler is in the same rarity as Sapphire and Emerald, but seems to be less desirable than both.
  
  
• Sapphire - This variation consists of 100% marbelized Sapphire. It is also a very desirable skin and is quite rare in the doppler stance as you are more likely to get a Phase 1-4 variation. This version of doppler is in the same rarity as Ruby, but seems to be more desirable than Ruby and has around equal desirability than Emerald.
  
  
• Emerald - This variation consists of 100% marbelized Emerald. It is, (like Sapphire & Ruby) very desirable and is quite rare in the doppler stance as you are more likely to get a Phase 1-4 variation. This version of doppler is the same rarity and Sapphire and Ruby - but drops separate from the other two which can only be found the Chroma series (Chroma Case 1, 2, 3), Prisma series (Prisma Case 1 & 2) and Spectrum series (Spectrum Case 1 & 2) cases.

The Ruby, Sapphire and Emerald variations have the exact same rarity and drop rate as each other, although for Gamma Doppler's there is only 1 legendary variant instead of 2, ostensibly making drop rates for Emeralds more likely than Sapphires or Emeralds. Despite this, Emerald and Sapphires are the most desirable and are similarly priced, while the Ruby often falls short as it's less desirable.



Ruby Picture (Bayonet):
Source(s): opskins (shut down as of 2020)

Sapphire Picture (Gut Knife):
Source(s): opskins (shut down as of 2020)

Emerald Picture (M9 Bayonet):

Source(s): opskins (shut down as of 2020)

This is the rarest "Ancient" variation of the skin:

• Black Pearl - This variation consists of 100% of the "Black" described in the Phases (most prominently Phase 1 & 3). It also shows signs of faded purple, faded red and faded yellow and can differ based on the pattern. Often, this is negligible but can warrant overpay for certain high tier collectors. You cannot obtain this from Gamma Doppler Series knives as it only goes up to Emerald in terms of rarity.
  This is one of the rarest knife skins you can get - as it is the only knife skin that is classified as "Ancient".

Black Pearl Picture (Flip Knife):
Source(s): My Old Inventory


While there are no other knives/skins which share the "Ancient" rarity as Black Pearl Dopplers do, game at this time, they are often significantly cheaper than those Legendary graded Doppler variants (Ruby, Sapphire, Emerald), but are simultaneously more expensive than Phases 1-4 by a significant margin.

I made this because I was bored a couple of years ago, and now it's one of the most viewed CS:GO guides. Thank you. :D