Individual waves are capped at 100% (ignoring skills). The UI is also capped at 100%. But the ‘true’ difficulty isn’t capped.
Consider a mission 6 waves long and a ‘true’ difficulty of 90%-140%:
- In the UI this mission would be shown as 90%-100%.
- The theoretical wave difficulties would be: 90%, 100%, 110%, 120%, 130%, 140%.
- The actual wave difficulties would be: 90%, 100%, 100%, 100%, 100%, 100%.
Now consider the same mission with a ‘true’ difficulty of 90%-100%:
- In the UI this mission would STILL be shown as 90%-100%.
- The theoretical wave difficulties would be: 90%, 92%, 94%, 96%, 98%, 100%.
- The actual wave difficulties would match the theoretical ones.
When it comes time to calculating your score/key boost however, the average TRUE difficulty is used. So in the first case, the boost would be (90+140)/2=115%, but in the second case only (90+100)/2=95%.
P.S. So what about skills?
- Skills are ignored in the UI (the mission will still be shown as 90%-100)
- Skills independently add to the wave difficulty when you’re playing the mission (so you can indeed be playing a max 140% wave on SSH)
- Skills are ignored in the difficulty boost calculations (because there’s a separate skill boost)