With the greater range of results from cards instead of dice, and the increased range of skill totals due to Modes, a small stress track of 2 or 3 boxes as Fate Core has doesn't quite work. Stress and Consequences thus work a little differently in Hand of Fate.
You still have 2 Stress Tracks, Physical and Mental. To determine how many boxes are on each track, you add together your corresponding Modes. Action Mode + Intrigue Mode = Physical Stress boxes, and Social Mode + Knowledge Mode = Mental Stress boxes. In addition, each track may have 1 additional box equal in value to your Will or Physique skill. So, for example, if your Social Mode is 1 and your Knowledge Mode is 4, and your Will skill is 3, you'd have boxes 1, 2, 3, 3, 4, 5. That's 5 boxes on the track plus an extra "3" box for your Will skill of 3.
Consequence are rated differently as well... instead of -2/-4/-6/-8, they are x2/x3/x4/x5. When you are hit by a powerful blow that goes well beyond your Stress track, you mark a Stress box and a Consequence and multiply the 2 together. So, say you are hit for 10 Stress. Depending upon which Stress boxes are still open, you could mark off the "5" Stress box an a Mild x2 Consequence, or the "4" Stress box and a Moderate x3 Consequence, or even the "2" Stress box and an Extreme x5 Consequence. Doing it this way has several benefits:
1) Your Stress track suddenly becomes very important, not just filler until you hit Consequences. Healing a few points of Stress in a battle becomes much more valuable because it makes any remaining Consequences more effective.
2) Because Consequences are used together with a Stress box, you can have a longer Stress track without extending the length of battles.
3) A character can absorb even a 25 point hit with a "5" box and an Extreme Consequence, and a hit that big is possible with the expanded numbers in Hand of Fate.
4) Your Consequences are only as effective as your remaining Stress boxes. A character with very weak Physical Modes = a very short Physical Stress track = relatively ineffective Consequences when used to block physical attacks. Conversely, the opposite is also true, strong Mental Modes = longer Mental Stress track = relatively more powerful Consequences vs Mental Stress.
I know this is a change from the standard Fate Core, but I'm interested in hearing what you think of it. I like it better than simply increasing the value of Consequences to-4/-8/-12/-16 or something, and it adds an element of strategy to the game. If you mark off all your high Stress boxes and lower Consequences, you'll have nothing to rely on if you suffer a big hit...