Yeah, to expound on what Arcaus said...
You construct a Deck out of your overall card pool with a maximum of 40 points. Each card varies in value from 1pt - 4pt (they may go higher, not sure). Cards have stuff like +100 health, +phys damage, +cool down reduction, pretty much standard stuff you can come up with, higher value cards have a combination of things. Cards are either Equipment or Upgrades. Equipment cards have three Upgrade slots that you spend your currency in game to improve. So like, if I start with an "Adamant Edge" that gives me +7.6 Physical Damage and +100 Health, I can then slot it with up to 3 different upgrade cards to further increase Physical Damage, Health, Mana, Armor Pen, etc... And most of those equipment cards give you a bonus once fully upgraded. Like the Adamant Edge is +15.2 Physical Damage when fully upgraded.
It is kind of convoluted, and the interface for deck building and upgrading in game is pretty crappy. But looking at some old screenshots it seems like they're trying to improve it. Cards have other restrictions that aren't immediately obvious. You have to buy card packs with in game currency points (think I read these aren't going to be RMT, so it isn't supposed to be p2w for them). It isn't a bad system, it just needs a lot of work to be more user friendly while offering flexibility. It feels more like LoL's item shop than something like DotA. Not saying it is a bad thing just a kind of reference.
The Harvesters are kind of an interesting concept. There are 7 on the map and not locked to any team. Four open at 3 minutes, Two at 6 minutes, and the final one at 9 minutes. So at 3 min your jungle or support can go plant a harvester on your side. It will start "harvesting" currency until it gets full. At an time a team member can run through and extract the currency. The trick is that anything harvested applies to the whole team, so it is global $$$. Getting them planted and making sure you're tapping them really increases the efficiency of the team. Of course, the other team can invade your jungle and destroy / take over your harvester spot. So you still have to pay attention and defend them. Can't be totally passive if the toher team is good.
Since there are no couriers or anything for upgrading items you kind of do your Recall cycle like in LoL. But what you can do is, if a harvester is planted, drop back in lane then hit the harvester, then recall.
Another thing is that creeps / minions combined with the absolutely paper thin towers and inhibitors make laning kind of crazy. Towers and inhibs have like 5hp and if you ignore a lane that has a little bit of an imbalance in creep equilibrium, or that even one person from the other team is pushing, you can lose two towers real quick. On one hand it really forces rotations and fights to occur. But on the other even though you have a 'Sprint' ability to move between lanes, it kind of sucks man. That's what I was complaining about earlier where everyone just wants to run around and team deathmatch. The meta and game sense hasn't really evolved to get the laning stage figured out. People just want to rotate, rotate. Just tonight I decided that a real good strategy may be to grab an early jungle camp, rotate 3 people mid / right / left immediately, and push the tower. You could get the T1 in like 3 minutes and there's nothing the other team could do about it. Shit just pushes sooo fast with any sort of coordination and there isn't enough mobility for team members to respond if they're out of position.
Anyways, I'm just rambling b/c it was a long night and pretty much only played this. So was thinking about a lot of crap. I'm tired.
