The first challenge between groups is about puzzles.
You can create crosswords, wordsearchs, anagrams, etc. using one of these tools:
http://www.discoveryeducation.com/free-puzzlemaker/
https://www.puzzle-maker.com/CW/
https://worksheets.theteacherscorner.net/make-your-own/word-search/
http://tools.atozteacherstuff.com/word-search-maker/wordsearch.php
http://www.anagramgenius.com/server.html
http://writingexercises.co.uk/anagram-game.php
Once you have done your job, create a file with your game and post it in the Padlet below. Finally you can accept the challenge of another group member and solve his/her puzzle, posting your solution on a file in the corkboard at the bottom of this page.
Here you have to corkboard where you can post the solutions to other people's puzzles. Please, write your name and the name of the people whose puzzle you are solving.