It a simple concept really. Get stamps for certain content in the game in the book. Get rewards, the more lines you get, the better the reward. Everyone will always get the 9 stamp rewards. One line is pretty easy. Two lines not impossible. But the third line, that is tough feels nearly impossible. Nothing to less but tons to gain.
I have come close once a few months ago. You definitely need to have the tenacity to keep shuffling to increase your chances, since you can only shuffle up to having 7 stamps, then you either get lucky and get three lines on 8 stamps or you gamble and get super lucky.
This my story. The first chance I had at 3 lines was during the FFXV crossover event. I was so close. Shuffle after shuffle, I got the lines where I wanted. I got 2 lines. I thought missed with the last one. I was doing WT and doing the shuffle game and got 2 lines, missing the stamp for the third line. So I do a retry and do a quick and easy level 1-49 dungeon (well a dungeon for the tome event). Check it off and miss. I have shot left, Retry again, and check it off...
I hear the noise it makes for getting the line and look. Low and behold I got all three lines. I can now retire. I will probably not see the three lines again.
I went with the cracked clusters and the 20 MGP cards.
Here are some screenshots.
Till Next time