Rerolling
Rerolling is the act of deleting your clone and then killing yourself. Instead of recloning you will be sent back through character generation, giving you another shot at building your character. When you reroll you lose all your current stats and skills. However, you keep any money, apartments, and items you had beforehand. Just make sure to put your stuff somewhere safe so no-one steals it while you are assigning your stats.
Rerolling is very common in Hellmoo, sometimes your build just doesn't turn out the way you want it too, or maybe you want to try something new; rerolling is a fairly quick process and if you know what you're doing it won't take you long at all to grind back your skills.
However even with all that you should always think it over before you decide to actually reroll, it can come as a shock to some previously strong players suddenly thrust down to the ranks of the lowly N-tags.
If you're curious about what other builds are like, you could always experiment with alts, instead of rerolling. The game allows you to have up to 3 characters, so you can experiment with a variety of different builds.
Things to do before Rerolling
When rerolling there are certain journals and items you should get that are exclusive to one character.
• Get all the swords from Kakuri Island, such as the Lotus Nodachi and the Fine Katana, and while you're on Kakuri you could get the clusternuke as well.
• Get the Deathsuit from the Null's Salvation Journal.
• Get the exclusive weapons from kill journals, such as the Copper Pipe from Charnold and the Hosaka Daikatana from Usagi Yojimbo or the Karnivore Gangleader's Jacket.
Or you could just go ahead and reroll, if you don't feel like being a completionist. The deathsuit and Clusternuke are the most valuable in my opinion. (Maybe the Fine Katana, Lotus Nodachi and the Hosaka Daikatana if you're rerolling to be blades.)