In this game effort is used to determinate the turn order. More or a higher effort mean this action takes longer and your next turn will probably be after the turn of your opponent, while a low effort might let you get an extra turn (two actions) before your opponent can act. Each card has on the top right the effort number, which is the cost for using this card. This number is usually between 5 and 12 and will be added to your total effort displayed on the bar above your character. After two actions (some cards can change it too) your turn is over and you have to wait till the total effort reaches zero again. The total effort is reduced for all units on the field at the same time and if two have the same effort then the unit waiting longer will come first ((need confirmation)). But some cards can change the total effort afterwards. Often you can see this in the campaign where the enemy reduces the effort by 3 when he get shot. Also there are stun effects that make every action cost additional effort, even an action that reduces the effort cost extra effort and then reduce it, making it almost useless.

So in short each action cost effort, effort has to reach 0 again for the next turn, effort can change after your turn and therefor change the turn order.

The effort system makes the game unique but unfortunately also more difficult to play. Normally you would expect an alternating turn order, but in this game it is key to manipulate the turn order to your advantage. You have to watch the effort of you opponent and decide who to attack first and how much effort to "use" so you get an advantage. Sometimes it is better to use a small weapon and end the turn, so you get to act before your opponent again. Or use heavy weapons and take out the enemy, but then have to sand around for a long time.

The good is the way this system allows you to manipulate the turn order and how light and heavy weapons influence the character. Heavy weapons make you slower, literally. Because you can use (almost) any card to move and when you have to use a heavy weapon for movement, it will cost a lot of effort. The same goes for reloading, heavy weapons usually require a heavy weapon for reload. While a heavy weapon make a lot of damage, a character with light weapons can make as much damage, because he gets an extra turn, so effort is a very important factor.

The bad comes from the complexity this system binges into the game. Sure some will say this is good while others will struggle with this for ever. It is not to 100% clear how the turn order will be, there are some hidden and some not well displayed factors that can change everything. Fist is something like the reduction of effort when shooting an enemies, you can take this into account but it is still a random factor. The later would be something like stun, you might have missed it during the enemy turn or you don't know how long it stays (this will hopefully be fixed later). But overall this is nitpicking, like saying chess is bad because you have to think too much.

The ugly aspect of this is how it change the play style, this is at least my view on this. You have to stay on low effort most at the time and this will lead to a play style where you end the most of you turns early. When you play against the AI it will prevent it from skip there actions as well to get an extra turn, so you eat less damage or none at all. At the end it makes the game slower as it could/should be.

(These are for the campaign, how useful they are in PvP you have to find out for your self)

• End your turn - if you don't have to, stay on as low effort as you can.
  
• Build you deck with enough low effort cards - around 1/3 should be low enough to use it for moving, you don't want to use 12 effort for your move.
  
• Use "free" time to reload or position yourself - when there is no enemy on the map and you have to regroup it is a good time to use expensive cards, especially when you have to burn time.
  
• Use cheap (effort) cards for reloading - sometimes you can reload your weapon with 5 effort pistols, they also can be used for moving or take out the 20 HP enemy. This is a part of the 1/3 low effort cards.
  
• Use close combat - even if you usually don't like to get close, they are cheap and can be part of the 1/3, also if someone ends up in front of you, you have them. Knifes are good, they can hit targets at your side or even behind you.
  
• Always have a character at 6 or lower - this is a simple way to prevent the AI from taking an extra turn.
  
• Take an extra turn - is your enemy above 10 effort you can just move in range and end the turn so you get 2 shots at him before he can move. But you don't want to stand in enemies range with high effort either.
  
• Take out enemies with low effort fist - but if you cannot kill him, don't let low health enemies get another shot at you.
  
• Be aware of special effects - some cards have lower costs for special actions, some cards can effect you or your opponent, some characters have special abilities. The number on top of the card is not always what you get, so keep your eyes open.