The other day I made a post on this topic saying how difficult I find it to answer this question objectively and answered in general lines, but without pointing out any practical parameters to determine real financial values.
According to his logic, based on the premise that you already know the game and can win approximately 50% of the battles played, then for example:
Spend $100 to build a deck to play in the Silver League.
Play 20 battles a day.
Win an average of 50% of battles = 10 battles
Earn an average of 130 DEC per day. (Since each battle won in the Silver League gives you an average of 10 to 17 DEC)
Complete daily quests and go as far as possible to get season chests, totaling an average of 70 chests in 1 month.
In 1 month you will have received almost 4.000 DEC just for winning ranked battles, which is equivalent to about 4 dollars, add the DEC and the cards of these 70 chests, and as long as you are not extremely unlucky, you will get at least another 5 dollars, maybe more if you are lucky to find any card most valuable.
This means that by investing 100 dollars you will get an average of 10 dollars a month, that is, a 10% return on investment.
This without counting possible additional winnings if you play tournaments.
This study was done based on the Silver League, but in the Gold League, this ROI may probably be even higher, due to the greater amount of chests that will be opened.
This also refers only to playing ranked battles, excepting other possibilities that can further increase your income, such as the tournaments I have already mentioned, rewards from brawl fights, card trading, participation in sweepstakes and contests, and creating content about the game.
I hope this post will help you take another step in answering this question of how much you can earn by playing Splinterlands and that there is no doubt that it is a great investment and what is even better: with fun! A lot of fun!
Images: PixBay, @splinterlands & Research Source: Quanto você pode ganhar jogando Splinterlands? Pelo menos 10% ao mês by @felipejoys