In which we learn more about failing forward

 Was running a published adventure - attempting to end a plague.  In order to do so the party was to slay the BBG, then dissect her corpse to find the 300 (!) words of the needed ritual, then assemble the pieces, then read the ritual 24 hours a day for 10 days at the site where the BBG was slain.  As you can imagine this would NOT lend itself to exciting table play.  So I consulted with my DM mentors and game-ified the ending a bit.

1.  Reduced the words to 30.  Once the BBG was slain they party searched for the pieces.  Each made an Investigation check at CR 0 to find a piece.  If they rolled 20 or more they found two.  If more than three pieces were found the CR went up 5.  If fewer than three were found there was an attack.  The attacks started at CR 1 and went up one each time.  This further reduced the party after slaying the BBG.

2.  Once all pieces were found three of the members of the party (The Chosen) were able to assemble it (via magic hand-waving.)  Reduced the ritual to just 24 hours.  One member of the party at a time could read using Arcana, Religion or History.  The CR started at 0 and went up 1 every hour.  Successful roll meant no attack.  Failure meant more monsters, starting where they left off.  Character could only read 4 hours at a time, then needed 4 hours rest.  As you can guess the first ten hours went pretty well, then the wheels fell off.  The encounters soon hit deadly.  

EDIT TO ADD:  I told the party of these rules.  Shouldn't have.  Shoulda just given a level of exhaustion after four hours and let them figure it out.

3.  We knocked off after 18 hours.  Six to go.  And I realized I probably escalated too quickly.The BETTER "fail forward" option would have been to make the encounter CR equal to the amount of failure.  So instead of CR 10 when they failed at hour 16 by only rolling a 14 it SHOULDA been a CR2.  Party is near death.  Gonna implement the above for the final six hours and hope they a) roll better and b) avoid the TPK.

If you find ANY of this useful do me a favor and drop me a note in the comments.