Help with cards.

I'd also recommend to take the time needed to prepare your card template carefully. Use different layers for different parts of the cards, it's extra important to have text and stats in a layer of its own. That way you can temporarily hide the other layers and focus only on text updates when those are needed.

Another tip is to make the background for your cards slightly bigger than they are supposed to (bleed) and add cutmarks to guide you when cutting them. This will make sure you don't get white streaks at the side of the cards.

I've done this for several prototypes, and my experience say that cutting corners here will only give you more job later on, so make sure the template include everything you need in the right places.

is it really that hard to use a ruler and measure it out yourself, even if you are concerned with proper dimensions of a card, it can be found with a simple search, im sure youll get several results with the keywords "playing card sizes". some print-on-demand sites provide templates if you really are intent on using a pre-made template

are you not cutting out the cards yourself with a paper cutter or even a pen knife? that sort of eliminates the bleed area problem since your cut will be controlled even if it is eratic. again i say, i am assuming this is for prototype purposes, correct me if i am wrong

if all you were concerned about was printing usable stuff, even microsoft word would have been good enough to make a prototype with. if you do not need multiple identical copies of a card, or if your cards have very little information that they are easily replicated, you could have just got blank name cards or index cards and write on them with marker

i think your problem is more on prototyping methods than prototype production, this will have to be analysed further with more information on your game. producing a paper prototype in initial stages should not take more than 2 days IMO

It takes about 1 minute to measure the card, go into illustrator and select the square tool, click on the screen and input the size for "h" and "w", and then copy and paste them onto your canvas. If you want rounded corners just use the rounded square tool.

I make them all the time.

mostly because this is a simply solved problem, even more so for someone who has experience in a graphic tool.

Just remember that when you get the cards printed at a printer (like The Game Crafter or another), they will be the ones rounding the corners (according to their die). You need to provide bleed around the card itself and as such the cards you upload to the printer will not have any rounded corners.

Just worry about getting the right size (2.5" x 3.5"):

https://community.thegamecrafter.com/publish/templates/cards/poker-cards

Here are a few templates for various programs (for Poker cards). If you want to not have the bleed, just TRIM the shape to match the cards actual size (2.5" x 3.5").