Interesting timing, as Splunk is running its regular Boss of the SOC and Boss of the NOC starting Monday. This is a simulated Security Operations Center, and Network Operations Center, used for training and competition :)
Past datasets for BOTS can be found at https://github.com/splunk?q=bots , and many related Splunk Blog posts about it can be found at
https://www.splunk.com/en_us/blog/tag/boss-of-the-soc.html,. These are freely avaialable, just download the data, copy to a Splunk instance (also free, as the data is already ingested), and you're good to go and start practcing.
Disclaimer, I work for Splunk, and am helping coach in the APAC BOTN next week.
I'll also link to the Splunk Attack Range, https://github.com/splunk/attack_range . This allows you to quickly spin up a small lab environment, then quickly hit it with a bunch of realistic attacks. All that data is then is then sent to a prebuilt Splunk instance for you to practice your investigation and analysis, and even integrate with Phantom, Splunk's automation system. Check out the video for it at https://www.youtube.com/watch?v=xIbln7OQ-Ak . Again, this is all free, no registration required.
* https://boardgamegeek.com/geeklist/39987/one-deck (my own attempt)
* https://boardgamegeek.com/boardgame/59655/rainbow-deck
But for something different, I suggest looking at the Decktet, https://boardgamegeek.com/boardgame/37301/decktet , which is an unusual multi suited deck, which people have ported games to use.