In this guide I will walk you through the basics, all the way to highly advanced breeding. With some tips and tricks along the way. Before getting started, here is what you must know:
BREED COUNT
Each axie can be bred a maximum of 7 times. Most breeders stop around 3-5 breeds because it becomes quite costly, this fluctuates with the price of SLP. At 0 breeds this is what we call a virgin axie.
Once your axies have bred, it will take 5 days for your offspring to develop from egg to adult.
SLP
SLP (Small Love Potion) is the token required to mate your axies and the amount of SLP needed rises with every breed. 
Each potion in this screenshot represents 100 SLP. However, this only reflects the amount for 1 axie. When you breed a 2/7 with a 3/7 for example, your total slp cost would be 800. Breeding 2 virgins together would only cost 200.
You can earn SLP in game by playing the PVE & PVP modes or you can purchase SLP on Uniswap
COST
During the breeding process you will charged fees for some actions and GAS fees every step of the way.
You will be charged gas fees when you:
1. Buy an axie
2. Purchase SLP on Uniswap or sync your SLP
3. Breed 2 axies together
4. Morph the baby axie to petite
5. Morph the petite axie to adult
6. list an axie for sale
7. delist an axie for sale
Since this game is currently on the Ethereum network we have been subject to the wild swings in gas prices recently.
Which has made breeding very expensive, sometimes as high as $100.00 usd for 1 breed process. But have no fear! Soon the game will be migrated to the Ronin side chain created by the Axie Infinity team!
This means that overall fees for transactions should drop dramatically!
The speculated target release for Ronin is in Q4 of 2020, sometime before the new year. First, land and items will be migrated then axies.
GENETICS
This is the most important aspect to understand as a breeder. Each axie has genetics passed down from their ancestors.
The 6 cards you see here are the dominant traits, abbreviated as D. Next are the hidden genetics known as recessive 1 and recessive 2.
Dominant (D) has a 37.5% chance to be passed on to the offspring.
Recessive 1 (R1) has a 9.375% chance to be passed to offspring.
Recessive 2 (R2) has a 3.125% chance to be passed on the offspring.
Even if you bred 2 axies with identical dominant parts, if those parts are not in the recessives as well...
The chance for your offspring to inherit the dominant trait is still only 75%, for each of the 6 body parts.
That is 6 rng rolls per offspring, and we all know how RNG can be right? Our goal is to cut down on that randomness by leveraging high genetic purity.
In order to view genetics (and make your breeding life much easier) i suggest you install this addon created by Freak, a pillar of the community.
At this time there is no addon for Firefox so you must use the Brave browser or Chrome.
This will allow you to view the genetic data and purity right in the axie marketplace, when hovering your cursor just below the axie's name. 
Whether you are a beginner or pro this is a tool you will be using often.
LETS GET STARTED!!
GENERATIONAL BREEDING
Axies cannot breed with their parents, siblings or half siblings.
They can be breed with aunt's / uncles, cousins and grand parents.
MATCH THE CLASS
When breeding, you should match the class.
There are 6 main classes, 3 secret classes and 3 types:
Tanks: Plant & Reptile + Dusk
Speed / Assassins: Bird & Fish + Dawn
Crit DPS: Beast & Bug + Mech
So plant with plant, bird with bird, beast with beast.
Why?
There are many reasons, for now I'll just say:
Each body part for an axie has stats relative to the class type.
A plant axie with 6/6 plant parts will have maximum HP
A 6/6 bird? maximum speed
A 6/6 beast? parts will have maximum morale which effects Critical rate and Last Stand.
If you mix a bird with a beast for example it has a 50/50 chance of being either and in most cases the stats would suffer greatly and there won't be card synergy.
You can also mix a plant with a reptile for example, since they belong to the same class type. You will still maintain most of the tank stat integrity and can get some good results for pvp. I would not recommend mixing same class types until you understand the game & parts fully though. You do lose out on some purity bonuses.
WHICH AXIES SHOULD I BREED?
This is a loaded question with lots of ambiguity. Generally it's split between PVP axies and high purity axies.
In order to breed PVP axies you need a deep understanding of the game which could take months to develop. A learning process you would go through with any other high learning curve game, understanding what every part does. Not to mention, balance changes occur often.
We will be focusing on high purity axies that also have strong body parts. High purity AND good in pvp. It is the best course of action in many ways.
WHY HIGH PURITY?
- Higher purity massively increases your odds of successful breeds. Even the failures will be good, useful and valuable.
- High purity axies get attack / defense bonuses in battle.
- 6/6 Pure axies will be a cornerstone in the upcoming land gameplay.
- It's much easier to breed in specialized parts, when your partner is pure.(92%-100%)
- Maximum stats for your class type
- Resell value, even after several breeds will still be higher than non 6/6, unpure axies.
WHAT IS A HIGH PURITY AXIE?
Matching class parts throughout the genetics.
Generally between 90%-100% purity.
Diving deeper into the genetics:
6/6 Dominant, 4-6/6 R1, 3-6/6 R2.
5/6 Dominant with 5-6/6 R1 would also be acceptable.
LETS COMPARE
For the longest time new breeders (myself included) would fall victim to breeding the wrong axies when they start out.
5/6 or 6/6 dominants with terrible recessive genes.
Lets take a look at an example of a bad breeding pair:
On the surface if you just look at the 5/6 dominant cards, looks pretty good right?
Well, now that you can look under the hood using Freak's genetic viewer tool, it's rather ugly right? Not the worst but definitely a genetic mess, with high chances of failure due to terrible recessives.
Lets run some quick calculations for reptile part chances in the offspring.
Eyes: 84.375% chance (inactive, unusable part)
Ears: 37.5%
Mouth: 75%
Horn: 40.65%
Back: 87.5%
Tail: 75%
It's important to note that your offspring will also have terrible recessives because both of the parents do.
Since your odds of hitting 5/6 or 6/6 reptile dominant traits is also poor, the child may turn out as a 3/6 or 4/6 reptile with bad recessives... With those skills and the variability in genetics, not worth much and it would a waste of money to further pursue breeding the offspring. You may also notice that the axie on the left has recessive traits that are not compatible with a tank. Lots of bird and beast parts. The one on the right does have some good tank moves in the recessives however the diversity would likely increase the odds of failed breeds.
Now. Lets look at an example of a good breeding pair.
You want both partners to have 5/6 or 6/6 dominant parts that match class. And at least 4/6, 5/6 or 6/6 R1. Bonus points if R2 also has matching class.
Here we can see the rows 2, 3 and 4 are all plant parts.
Therefore, it is 100% certain when we breed these axies we will get a Plant horn, mouth and ears in every offspring with this pair.
Matching class part calculations for the child:
Eyes 96.875%
Ears 100%
Mouth 100%
Horn 100%
Back 93.75%
Tail 90.625%
Your offspring will have heavy plant recessives, very high purity. Dominant genes also locked in. Even if the breed turns out "bad" it will still be a 5/6 with very high genetic purity in recessives.
Valuable for sale, breeding, battle and land play. A large majority of your breeds will be great.
Serious is a meta card and we would have a 56.25% chance for that.
Rose Bud, Cactus and Beech are all good horn cards. We are guaranteed to get a good horn card with every breed.
Pumpkin is a top meta back
Carrot is a top meta tail and Hot Butt is... alright.
The odds on the meta cards could be better right however it is also quite rare to have Multiple meta cards with Dominant and R1 genetics.
I hope you understand now just how important genetics are.
RECESSIVES & PURIFYING PARTS 
You won't always be able to get the ideal breeding setup at first. So it's ok if you go with the best you can afford to get.
This is a breed from a friend i have been coaching. She is aiming to create the first 100% pure plant and from this picture we can see that it will also have a good chance at being very meta, usable. While she got very lucky with this breed, you can see just how chaotic recessives are.
Carrot D and R1 on both parents for a total of 4 Carrots in the best positions, yet the offspring came out with Carrot on D and R2.
Pumpkin D on both parents, R2 on one. Yet the offspring came out as 100% pure pumpkin.
Cactus D on both parents, diverse horn genetics. Came out as D & R1 cactus in the child.
Herbivore on D & R1 for parent, completely eliminated in the child in favor of serious.
When purifying parts you want to have between 3-5 matching parts in the breed.
So in the dominant and recessive genes for both parents you would want at least 3-5 carrots, 3-5 pumpkins in this case. Then you continue to breed with other pumpkin carrots of high purity until one day you have lots of 100% pure parts that you can replicate in a loop. In this example you would then do the same for cactus and serious. And eventually mash several pures from each group until you have an entirely pure line of meta tanks.
This is not only the longest approach, the most time and resource consuming. It's also risky because you can then neglect the other parts. You might end up with 100% pure pumpkin and carrot but happens if your eyes and ears become off class? a 4/6 would be hard to bring into purity and again, very time consuming.
EXPENSE
Naturally, higher purity axies tend to cost more. That's because it takes a lot of time, care, effort and ETH to create them. Most players have been breeding "pvp" axies so good high purity axies tend to be in short supply with the exception of birds, beasts.
While they do appear to cost more you will actually be saving tons of money and this give you an opportunity at making profit. The resell value is much higher for the parents and offspring going into the future of your farm.
In the reptile example above, the resell value of those axies and the offspring. the costs of breeding wouldn't be worth much at all. All the bad breeds and money wasted on gas.
With the high purity plant example, you can resell those for a decent price even after 3-4 breeds. They are still very useful in PVP, will be useful in land play & can be used for breeding in an emergency to repair genetics. the cost of breeding is offset since a large majority of your breeds will be successful. AKA, you can quickly make your money back.
Of course the most desirable would be 100% purity but at the moment only 1 class has reached this level of purity, Birds. The base price for 100% pure virgin birds is currently 1 ETH. Rightfully so because with enough time you can create an infinite amount of pure birds with just 3 100% birds.
If you want to start your farm off right, go for high purity axies with a couple of meta or decent parts at least. The initial cost will be higher, your mid & long term cost will be lower, it's worth it.
BREEDING METHODS / APPROACHES
I just mentioned that high purity axies tend to cost more because they're expensive to make.
So, lets run through creating a rare, higher end, ideal axie from SCRATCH!
***Disclaimer i DO NOT recommend this method at current gas prices. Wait for Ronin sidechain before even considering this approach***
FROM SCRATCH
3 months ago, was on a mission to create a specific aquatic. Back then fish were not popular so what i had in mind simply didn't exist, it was not being bred.
Had to start from scratch. For this method i will be detailing a certain build, but you can apply it to literally any build, any parts you want.
Want this fish to have: 6/6 purity
Mouth: Lam
Horn: Shoal Star
Back: Perch
Tail: Nimo
The idea is to find 2-3 axies with at least 2 body parts we want.
Then, another 2-3 axies with the remaining 2 body parts we need for this build.
First, we head over to the axie market place to use the search filter.
Since perch is an incredibly rare part will we start cross referencing with this part.
For parts we will scan through Perch x lam, Perch x shoal & Perch x nimo available in the market.
In the general section of the filter we will only be looking at aquatic class for now.
At the moment the only pairing for aquatic axies on the market with is perch x lam.
So i would pick up one of those from the market if the breed count is 2 or lower and the price is reasonable.
But wait, still need 1-2 more right? So, lets see if more exist outside of the market listings.
Adjust tab to "Not for sale"
This will show you all the axies in existence with the search criteria you outlined.
Now i would take a look for low breeds and high aquatic purity, whatever is available.
Then, contact the owner to see if a deal can be made for a reasonable price.
Lets say i acquired one from a deal.
Okay, that would bring our total to 2.
If there was no other option i would expand the market search to include all classes for the third perch x lam.
If there is one of high aquatic genetic purity at a good price, may purchase. Or you could take a risky gamble and only go with 2.
Repeat these steps for the remaining other 2 parts (Lam and Shoal)
this is what you're breeding tree would look like with 2 of each. (Axies represented as shapes) 
Using only 2 of each is a huge gamble.
The idea here would be to take the best Perch x lam child and breed it with the best Nimo x Shoal child.
Then hopefully you get the axie you're after. If all should fail, you could always breed the result (red triangles) with the parents to try and increase the purity of the parts or breed the "2nd best" offspring from each batch to try again.
This is what it would look like with 3 of each, the proper AB C method: 
Note: Do not breed C, with A & B. Only breed C with the offspring of A & B.
1. Breed the PerchLam parents together twice. (A & B)
2. Breed the generation 1 children with the unrelated Perchlam (C) once or twice each
3. Breed the generation 2 offspring with the parents (A & B, Now grand parents)
4. (optional) You can breed the gen 3 children with gen 1 if necessary, you can infinite loop this.
Repeat these steps for your 2nd set of axies, the Nimo Shoal batch.
5. By now you should have PerchLam in the dominants and at least R1, Same with the nimo shoal.
Select your best breeding candidates of high purity then breed them together.
Your best Perchlam and your best NimoShoal.
And you should be able to pull off the target breed! 
From here you can also take your 2nd best Perchlam & Nimoshoal's and breed those together 2-3 times. Then use the best offspring to breed with your final result for even more!
It was costly totaling around 1.6 ETH but the result is a one of a kind fish. Out of over 150,000 axies this is the only one of it's kind to exist.
(Filter set to 6/6 aquatic with the described parts)
That's about 20 breeds with 4-5 tx per breed cycle. 80-100 Transactions where you would pay gas.
Which is why if you want to do this method, building from scratch, you must wait for ronin otherwise you would likely pay 3-8 ETH at our current gas rate between 60-150 GWEI.
In most cases you can find ideal builds, already built far cheaper usually ranging from 0.2-1.0 ETH, Depending on the build, class & breed count, scarcity / saturation & purity.
ABC METHOD / GENERATIONAL BREEDING
The ABC method was detailed above. It is the most popular breeding method for several reasons.
1. You can keep the breed count / SLP cost low.
2. This method will allow you to breed with grand parents.
3. You can loop this indefinitely.
4. It's flexible. After a few generations you can choose to breed more and expand your farm.
5. You can use this method to slowly add META parts to you a high purity line, until you have your ideal build.
6. This method works well for purifying class parts and individual parts.
Whether you use a mind map or MSpaint it is important to keep track of your axies and breeding plan, so you don't accidentally screw up your breeding tree. If you accidentally breed the wrong axies together, like A+C and A+B, Your child axies will not be able to breed with any of the axies in your plan. 
When you rename your axies it's good practice to label them by their generations or designated roles.
Such as parent 1, parent 2. Gen 1 children. Gen 2 children. gen 3. Etc.
WHAT ARE GOOD CARDS WHAT IS META?!
This is yet another loaded question. Axie Infinity is technically still in Alpha and changes to parts are made often. The META changes.
There is even a new version of battles coming out soon, which could flip everything on it's head! When land gameplay is released perhaps there will be specific builds for that as well.
Whats great today may not be great tomorrow. To answer this question will come with experience but i don't want to leave you hanging either.
I'll direct you to some tier lists so you can get a ballpark idea...Just remember there is a layer of subjectivity in tier lists and this should not be solely substituted for experience right, just a general idea.
Many builds rely on synergistic combinations of good parts.
HOW HARD IS IT TO BREED A 100% PURE?
Deceptively difficult! I know dozens of breeders who continuously bred 93%-98% purity axies together and after 8 generations never got a single 100% pure.
This is because recessive genetics can be very, very stubborn & tricky. It's not uncommon to have the same off-class r2 gene for ages.
Once you do have some 100% pures every breed you do will have a 100% chance of being 100% pure. Max stat axies.
WHAT ABOUT PVP AXIES?!
Yes there are definitely some great axies that are not pure. Most often, Plants will be mixed with cards from other classes.
However this form of breeding usually has a higher degree of failure and uncertainty. While these 4/6 and 5/6 builds can be great in PVP they will miss out from the Pure boosting items in land gameplay. For example there is a bug class card named leaf bug which only works when you combo it with a plant card. It's great and works very well but when it comes to breeding much more difficult to manage. When done right, Typically you would get a 6/6 high purity Plant with lots of plant recessives then a 4/6, 5/6 plant with leaf bug and hopefully some decent recessives. Breed them together and the result should be decent. The problem with this is:
mixed class pvp axies tend to have very messy genetics. The lines have not been purified. The meta constantly shifts and if that part becomes redundant you will have a hard time maintaining value in that axie. The future breeds for greater purity would become challenging as well, with a lot of RNG uncertainty.
Once you have enough high purity axies it makes sense to work on those builds, if you so choose because if the builds go wrong you have lots of pure's to fall back on... to try again.
If you don't and your mashing together 4/6's hoping for a great pvp axie, well... you're going to have a frustrating time and lose some ETH because it might take many generations to get what you desire.
Remember, 6/6 pure axies with good parts are also very strong in PVP. And they tend to weather the sands of time much better.
RECOMMENDATIONS
To wrap this up i would recommend aspiring to build high purity axies that also have meta parts. The best of both worlds.
ALWAYS check the genetics when buying. Don't just believe in the name of the axie that the seller wrote.
Look for 6/6 or 5/6 axies with strong genetics and some good meta cards. Get a few similar ones of the same class type you want to focus on.
Make sure their breed count is either virgin or below 2. The one exception to this rule is 100% pure. You could pick up a few 100% pure at 0-4 breeds then make some 100% virgins from those, although it would be a little costly in SLP and the resell value wouldn't be too high.
Here are a few tools that will be useful for breeding:
https://freakitties.github.io/axie/calc.html
https://freakitties.github.io/axie/jeans.html
https://freakitties.github.io/axie/breedAssist.html
https://axie.zone/ (Can view genetics through the "finder" option and see some meta builds. There is another tier list here as well)
Breeding has a steep learning curve but if you study this guide you'll be ahead of the next generation of breeders. It will take some time to learn about the game so come join us and you can study before Ronin is released :) If you have questions the community can be helpful in answering. Join here:
Axie Discord
Main Axie site
Marketplace
Take care and good luck!
- Asura
