Now let's talk about the system a little. If you've looked at DoubleCross, Log Horizon, Night Wizard 3, TNX, or games like that, some of Kami will look fairly familiar. It's an SRS-derivative game, but unlike a lot of SRS-derivative games, Rikizou has taken the time to really make Kamigakari something special.
The base dice mechanic of the game is simply 2d6 + stat, roll equal to or over. However, let's skip all that and talk about the Spirit pool. This is the mechanic that makes Kami shine. What that is, is that at the start of a new scene, or at the start of every round of combat, you roll 4d6. Then, you take those dice and set them aside. They're now a "stock" of dice you keep and control. Let's say you roll 2, 3, 5, 5 -- that's your Spirit pool now.
Now during play, you're allowed to swap dice you've rolled, with dice in your Spirit pool. So let's say you need to climb a wall. The difficulty is 13. Your Strength is 5. You roll, and get a 5 and a 2. So 5 + 5 + 2 = 12, not high enough, you fail...
...Or would, but your Spirit pool has 2, 3, 5, 5. You think a minute, and then swap the "2" you rolled for the "3" in your pool. Now your roll is 5 + 3 + 5 = 13, you win! And your Spirit pool is now 2, 2, 5, 5.
You must always take "some part" of your roll, so one die of your roll is off-limits. This generally means, in a 2d6 roll, you can only make one swap. But if you somehow end up rolling 3d6, you can make two swaps, and if you roll 4d6, you can make three, and so on.