I'm developing a new RPG and was wanting to use things readily available in most homes so as not to create a burden to play. The solution I came up with was 2d6, which the max is 12, and a deck of cards which Aces = 2, and kings & jokers (if used) = 13. The reasoning behind this is that it would be 1/4 of a d100, which quite a few games use.
I’ll likely use this for playing modern day/near future games. I’m aiming for it to be reasonably rules light, probably FATE- or GURPS-esque.
One of the things I was going to do with it (to make things interesting) is that one card could be played per level of the skill (or whatever), but above the 1st card, complications would arise, so players have to balance "do I add more cards in order to increase the likelihood of success... or do I simply let this fail". BUT in order to understand this more fully, I need the curve to analyze

