There’s a lot of legal babble here, but I’ll try to break it down:
Back in 2003, Immersion sued both Microsoft and Sony for the use of rumble in their controllers, as they originally held the patent for the technology. From this lawsuit, Microsoft was ordered to pay Immersion $26 million. Ouch.
However, being the sly bastards that they are, MS included a clause that required Immersion to pay them a portion of any money obtained from Sony as part of additional litigation.
Later, Sony was ordered to pay Immersion $90 million over the suit. Double Ouch. Microsoft was not paid per that earlier agreement, so they sued Immersion.
Finally, Immersion settled out by paying 20.75 million to Microsoft.
The end result? Microsoft made out like a bandit, paying in a little over $5 million for the use of rumble in their controllers. Poor Sony has to pay so much more.