First of all, sorry, English isn't my native language.
So for the cards…
First, cards effects are REALLY GOOD, it can change the whole gameplay of a character or transform the worst weapon into a killing machine.
(example : IUNE's "last wish" gun goes from pure garbage to high DPS weapon when build properly)
Having a good pool of rare cards allows the character to be more versatile because he has many more builds possible - especially if you get some mercury points and unlock the second or third equipment slot-.
Every player should spend time checking cards and do testing.
You have 2 types :
- FACTION CARDS
It's the same pool for every character of a same faction.
- CHARACTER CARD
Unique set of card limited to only 1 character.
You can DRAW a whole new set of cards by using the button under your actual set of 4 cards.
When you DRAW, you leave every cards you had unless you LOCKED it.
It means you spent 800 faction points to keep this card locked and keep it even if you draw.
You can unlock it when you want, it's free.
You have the possibility to DRAW either RAIDER or ANTAGONIST cards,
If you want a Raider one:
you'll need to be on a "Raider level" (means you have a "R" on the top left of your screen)
If you want an Antag one:
you'll need to play as antag (1 time if you win and 2 if you loose) and get the "A" next to your EXP gauge - happens after a LVL UP.
When you lock a card, you lower your chances to draw another card you want, just because the slot will stay full. So, the more cards you have locked, the lower are the chances to pick a card you want.
I advise not to lock basic cards, only RARE ones. I think it's a loss to spend 800 faction points - especially at low level - to keep a card which has a better version and it makes it harder to get its rare version.
RARE cards are hard to draw, just be patient.
So, I suggest to prioritize :
0 - Play you character so you know his strengths/weaknesses
1 - You check every cards for this character (FACTION / CHARACTER CARDS)
2 - You chose cards you want the most - don't even think you'll get 4 cards you want, just focus on 2 it'll take a loooooong time to get them unless you're really lucky.
3 - You farm faction points so you can draw (instead of drawing cards everytime you have 4.800FP; wait for like 20.000FP so you can draw x4 and lock x1)
4 - If you find a basic (grey) version of the card you want, equip it and go do some testing. DON'T LOCK IT. It might be not that representative since some rare cards can be really better than its normal version.
5 - Rince and repeat (3 - 4)
6 - When finally you draw one of the card you wanted, DON'T IMEDIATLY LOCK IT -> GO TEST IT
7 - If you like it, go on and lock it for good
8 - Now you can chose a second card to pick and start all over again
Don't forget that :
1 card locked = less chances to pick another card you want
2 cards locked = 2x less chances
3 cards locked = RNJesus
Hope I understood your question and answered it
If you want information about builds, I highly recommend youtube channel "HIHSASUKE"
https://www.youtube.com/channel/UC_z9WQvAYnYtcnlsrvBnDMAhis content is sooooooo good, I don't agree all the time but he gives good tips and one of the rare spacelord youtuber.
If someone knows other youtube/twitch channel, please share it !
EDIT : The exp boost on card is random
