How does PvP work in Hardcore?

Without getting griefed with misinformation. I started a new character and just hit act 2 and i see greuth with an option to join pvp. What does that mean? what does it entale? There is no information about it on here. If i join and die does that make my character go to softcore? If i die do i stay in hardcore but lose all my equipment? I dont even want to click on the option for fear of it just magically transporting me somewhere and bam, out of my control.

Secondly i'd like to ask. I dont understand these races. Do we just make new characters using equipment we've saved up? Does it matter if its hardcore or softcore. I dont want to fiddle with it because i dont want to get griefed because i have no clue about how this stuff works.

When you PvP you get teleported to an arena when an opponent is found. HC-PvP deaths are not permanent so you're not moved to default for dying there. There are also no ill effects for dying in PvP at the moment (no gear loss etc). GGG has stated they are planning on adding options for PvP with permanent effects (like cutthroat leagues) in the future, but they will be optional of course.

For races they make a short temporary league (usually HC) where people must make fresh lvl 1 characters to compete. It's a brand new league so you will start with nothing in your stash (it's supposed to be a contest of skill, not about who has saved up the best twinked equipment). After the contest the characters are migrated to the regular default/HC leagues.

-Ropetus