Hello Splinterlandians old and new alike!
There are a lot of intricacies to this game that I wish I could find a guide for but since I haven't found one I thought I'd jot down some notes for others to hopefully glean some insight from. This isn't advice. I'm in no position to offer any. Just food for thought I didn't have that certainly would have made a difference in some of the decisions I made, for better or worse I can't say. Whether you're new to the game or not I hope everyone will find something useful here. If you've been around for a while please be kind enough to offer corrections or additional info in the comments.
Some of the things that come to mind that seem worth noting include:
Dark Energy Crystals (DEC) and how they are earned and used.
The different editions of cards and the pros and cons of hodling or collecting each.
What little I (think I) know about Steem Engine and how it's essential if you're playing for profit.
Playing for profit. Expectation vs. Reality and why.
Gold Foil Cards. They're more than just shiny collectibles!
Burning cards. Pros and cons.
Market value vs. burn value.
tournaments:
buying packs and orbs vs. buying from the market.
Peakmonsters: get kick backs for buying through this portal!
renting/leasing cards
Playing multiple accounts
Dark Energy Crystals (DEC):
The introduction of Dark Energy Crystals (DEC) brought about a whirlwind of changes to how the economy functions. When I first discovered Splinterlands (formerly Steem Monsters in those days), beta edition had just been released and battles where yet to begin. At that point I could buy packs, play the game or collect and try to sell on the open market.
There wasn't really a way to easily know what a cards value was. I just looked at what it was worth on the market and put it up for sale for a few cents cheaper. DEC changed that significan'ty in a number of ways. Since DEC can be used to buy promo orbs or exchanged for liquid STEEM (more on both later) a seller isn't as vulnerable to the whims of the market. Often a card will be listed for a price much higher than the DEC burn value but having that floor shifts the balance to the sellers favor to some degree.
First, the obvious usefulness of being able to instantly liquidate opens up pretty much total control over your assets. You surely wouldn't get what you want for them but if you absolutely need to cash out the option is there. I don't have an eye for the market but I'm certain there are those who earn regularly simply buy following the trends, buying low and selling high. I can also see it coming in useful as a way to catch great deals that spring up.
Second, when you burn a card it's gone, period. So the value of all the others goes up slightly and there's less in the pool. The seller now has the power to influence the market in a new way, especially if the asset in question is particularly rare. No one wants to give you $10,000 for a GFL Lord Arianthus? Burn the mutha! You don't have to suffer that humilation. I'm just kidding. Later I'll tell you why you shouldn't burn without looking into other options that pay more.
Third, DEC has it's own market value! Let that sink in for a minute because I think it's quite revolutionary. A token you earn for playing a game can be exchanged for a VERY WIDE array of other tokens as well as cryptocurrency, which can be sold for the currency of your choice. I haven't been watching it closely but I have seen DEC rise and fall in value so it seems like it would pay to hold until a spike. I personally end up buying promo orbs or exchanging for STEEM for Beta packs, because I'm more or less addicted to the lottery aspect of drawing that $3,000 golden ticket that I can sell to go on a rampage upgrading my deck. DEC will probably come up again, but the above would've been useful information to have sooner, and that's where I'll pause for now.
Editions: Alpha, Beta, Promo, and Rewards; Which is right for me?
For the newcomer the editions break down more or less like this. Alpha cards where the initial release, then beta. When I first started playing I was getting beta cards for daily quest rewards but a few months ago reward cards were released and now those are the cards we earn for completing daily quests (along with DEC for winning matches). Promo cards, from what I can tell, come with the launch of someting new or as a fundraiser. The most recent promo orbs were released with the introduction of DEC. There's been at least one more, that had some new dragon cards.
Alph cards at this point are all but sold out. As far as I know you can't get them from the main site anymore. Last I saw, about a week or so ago, there were less than 20,000 packs left on Steem Engine. I feel the more exact number was around 13,200, but I'm not certain. The point is if you didn't get in early and build a playable deck you'll be hard pressed to do it now. That's not to say it isn't worth getting a few before they're gone though. They are definitely worth more on the market than beta cards or reward cards. And, like gold and promos, they earn more DEC when played in ranked (more on that below, too).
Beta cards are what you get currently when you buy a started pack on the main site. There are still around 350,000 booster packs left, but that's down from 900,000 from the initial launch, so I'm not expecting them to last through the end of the year, especially as fomo (fear of missing out) kicks in and people start scrambling for them. You don't gain any DEC bonuses for playing beta cards in ranked matches.
Reward cards are the cards you get for completing daily quests and at the end of the season. If you're just now coming into the game this is going to be the bulk of what you're playing with unless you want to throw down a few hundred dollars to straight out buy other editions. Luckily you can trade DEC for STEEM and buy any edition cards from the market or packs or orbs if you like being surprised by what you flip over. None of that is to say rewards cards aren't worth having. Many great abilities came along with the release of rewards cards and I count many of them among my favorites.
Promo cards are what you get from orbs you purchase with DEC. On the whole they are worth more than beta and reward cards. Orbs cost 2,500 DEC, which if my math is right, but DON'T COUNT ON IT, is worth about a dollar for every thousand, putting orbs at a cost of closer to $2.50 a pack vs $2 for beta packs. I don't know what the few remaining alphas are going for but I think it was under $3 last I saw. Promo cards earn additional DEC in ranked matches.
Gold Foil cards can be any of the cards above. They have a considerably higher DEC burn value than regular cards as well as a higher market value. Gold Foil cards earn additional DEC in ranked matches and that stacks with other bonuses. I.e. A gold foil card earns a 10% bonus, but a gold foil alpha or promo card earns 10% for each bonus for a total of 20% each up to a max of 50% (I think). I think it works out to being able to double your DEC capture with everything max.
*Edit: Each individual card can deliver a max 20% boost (gold and alpha), but there's no maximum for how high that boost can go. If you played 7 (including summoner) alpha, gold cards, you'd get +140%, plus any win streak bonus, which maxes out at 50% so all up, that gives a total possible of 190% extra DEC (almost triple) that's technically possible, assuming 100% ECR (capture rate) and a high enough mana cap.
Before continuing, I want to point out that I'm still learning as I go. There are so many ways to earn a little here and there on the STEEM blockchain as a whole and it's been somewhat overwhelming for me at times simply to snatch a tidbit of useful info as it flew by in the whirlwind of things available to discover here, so please bear with me when I have to be vague. I'm piecing it together as best I can at the moment and welcome corrections or insight gleaned from the experiences of others in the comments.
Burning Cards: Should you do it?
For me the short answer is I don't know. I burned quite a few gold foil cards upon the arrival of DEC and promo orbs and got a lot of good stuff form the orbs I bought, but had I been more knowledgeable I may not have done so as freely as I did. I did that before I found out that 
I think it's brilliant and I applaud the idea and I think there's a whole lot more than can be discussed around it, but this is meant to just touch on a few things that might be easily over-looked early on.
Market value vs. DEC burn value:
As it would indicate, market value is what people on the market are asking for a particular card. The DEC burn value is the number of Dark Energy Crystals you get from destroying that card and taking it out of circulation permanently. DEC value doesn't fluctuate. If a card is worth 700 DEC it always will be, to the best of my understanding.
Market value fluctuates like crazy. I've seen cards listed for $200 slowly fall until someone grabs it at $80, then see it selling for $150 2 weeks later, even though the DEC value would indicate it's only worth $50 or $60. In addition to the actual rarity of any given card, there's also the perceptions of it held by each individual that can drive the price one way or the other with little regard to it's actual functionality. I don't think that happens often, after all, I'm convinced each card has a function and a place in the deck and most stand on their own merit... but there are a few "step children" that have a market value exactly equal to the DEC burn value. I often fantasize the ones that survive "The Purge" will someday be priceless.
Moving on,
The Market:
There are multiple ways to acquire cards. You can win them for quests and season rewards, & contests, you can buy them in packs or orbs, someone can gift, loan or lease to you, or you can buy from the market. I wish I had known about https://peakmonsters.com/ so much sooner than I learned of it. After you spend a set amount through this portal you start getting dividends back and there are tiers you can rise to for bigger returns. I'm pretty sure you can buy beta packs through it, as well, but I don't know the details of how it might affect things like your progress toward maverick status. However, I do know that if yo feel the market price is too high for a given card you can make an offer along with others until someone finally entices the seller to settle. It's definitely a place to check out!
*Edit: Cards bought through Peakmonsters deliver all the same benefits as buying through splinterlands.io. They count toward Maverick status.
Peak Monsters also has a system in place to allow one to rent cards from others for play or to others for a price. I've spoken to numerous people in discord that are renting gold foil cards to max DEC and to compete in the higher paying gold foil only tournaments. Many of them seem to be making balanced returns. I haven't tried it myself but I think it warrants further examination.
Regarding choosing between packs and promo orbs there are at least a couple of things to consider. Promos cost a little more and are worth more and there will be fewer of them in existence. Beta packs are slightly more cost effective and send 5% to the affiliate you linked through when you started your Splinterlands account. More on the affiliate link below.
If you're playing the cards rather than just trading or hodling, I've found some of the cards I've gotten from promo orbs seem to get used A LOT. Also, I've noticed that often when new cards are released there's a frenzy that drives prices up and often a few weeks later they settle at a much lower price than they were originally going for. Just something to keep in mind but don't assume it'll always do that. Markets are slippery s.o.b.s.
So, I don't know what your time is worth, your share of the power and internet bills, and what you consider profit, but I've made very meager money playing this game and I'm certain there are people making significantly more than I am, because they've figured how which of their own cards to rent out and which to lease from someone else to maximize profits from daily quests and season rewards and high paying tournaments, and trading and it's enough to make my head spin. As far as how much you can expect to earn, it's really mostly a matter of how much time and money upfront to invest. I imagine there are people in this ecosystem making more a week than I do from my full time job and if you're one of the one's with a knack for connecting all the dots you could do better than some.
Before I dizzy myself into the darkness I need to tell you about https://steem-engine.com/
I'm still really new to it so this, too, will be fairly cursory, but it's a wonderful tool. The short of it is you can send your DEC (or many, many other tokens listed there) to your steem engine wallet and sell it for STEEM (pegged, which you withdraw into your Steemit wallet as STEEM). It still makes my head swirl to look at all those graphs and numbers and fractions, but the bottom line is like all other markets those numbers go up and down and if you have an eye for knowing which is happening at any given time I imagine significant money can be made there, depending on what you stake.
Dividends!! I almost forgot to tell you that you can also earn DEC daily by delegating to Steem monsters. I have a little over 300 SP delgated and my payouts have ranged from the low 40s to the low 70s so far without settling anywhere for long.
Playing multiple accounts:
At lower levels it doesn't take terribly long to earn enough reward cards to level up a few times but as cards get to higher levels it begins taking 50, 60, and more cards to get to the next level. Rather than combining them immediately, or letting them lie around you can use your earnings to start a new account and send them to earn cards via daily quests and season rewards until you've gotten enough to send back to the primary account at a higher level. This is a good place to mention affiliate links. If you start an alt account with your own affiliate link you get a 5% return on all beta packs the alt account purchases (alphas, too, I think). However, that does put your alt in line to surpass you in your progress toward maverick status.
Edit: I just found out you can also delegate them to a 
Cards won are instantly burnt via ottermaker, and that DEC is also divvied up. I'm looking forward to exploring this further.
This isn't an exhaustive list of what there is to know surrounding Splinterlands but I hope it's been helpful toward pointing out some of the places to look to make your time here well spent and things to consider when learning how everything works and ties in together. If you have anything you'd like to add or address, please share in the comments. I hope this is the beginning of a discussion that we can all take something away from.
Feel free to ask questions in the comments or share anything I left out you feel deserves mention. Thanks!
Very special THANK YOU to 
