Dungeons & Dragons 5e
A great wizard has discovered a parallel world in the multiverse which is very, very different, full of tropical forests and great lizards. He is conducting research on the strange plants and the origins of draconians. Sadly, not everyone he has enlisted has come back...
You are charged to explore new lands, forage for plant samples and possibly capture live specimens, and, should you be able, track down and find evidence of the fate of previous parties to head through the portal. Every day will be a risk, and the wizard can only open the portal once a day - if you are not back at base when the portal opens, you are condemned to another day trying to survive.