Do I roster and level bad 2*s?

Ideally you want to roster and champ every single character that's a 2-star and above. Once you don't rely on your 2-stars to win matches for you it's a widely accepted practice to start 'farming' them (max-champ, sell, start a new version for more champ rewards).

Another reason to roster every character (even if they are 'bad') is the four essential nodes in PvE that requires you to have a (rotating) 2/3/4/5-star on your roster to even play them.

This of course all assumes you have the roster slots available, which start to get pretty pricey. If you've ever been tempted to spend money on this game, use it for buying HP and roster slots - it's the best value for your $$$.

You're going to be a little thin on roster slots until you're well into the 3-star tier. Sometimes you have to make hard choices. If given the choice between rostering a 2-star vs. a 3-star... go with the 3-star. 2-star covers are a dime a dozen and easily regained.

General_Tojo said:

That's what I thought, thanks! But is it worth selling a champed 2* for new 3*s?

I wouldn't do that. If you're no longer relying on that 2* to play the game on a regular basis, I would sell them and re-roster them (or another 2* if you have a bunch of covers), which will (eventually) result in more HP, CP, and 3* covers for you.

I want to talk to the version of you that will be playing 6 months from now:  you're gonna regret selling Bagman.  You will end up in a place where you're not stressing over slots. You'll have an undercovered Bagman maybe 0/5/0, and will look regrettably look back at a time when you had those other two colors sitting in your queue and you sold for iso.

*I just champed mine and it felt awesome lucking upon that 13th non dupe cover.

   I can only speak from my perspective, but for me champing every 2* (except for bagman; who's not currently even on my roster) has been the smartest move in the whole game.  I can't tell you how many times a max champed 2* has given me the HP I need to buy a new roster slot or give me ISO to champ a 3*.  Plus the XP you get from training a champion will get you closer to moving up a rank, that gives you even more ISO.  What I did when a started about six months ago, was focus on champing all 2*s but keeping only the top tier 3*s, if I was able to.  If you do a search for character ranking you can read which 3*s meet your play style and focus on those, or set those as bonus heroes. I personally would recommend 3* Iron Man 40 and 3* Dr. Strange first.  I have every 3* rostered (and champed except for 8) and of all my champs, IM40 and Strange get used every single PVE.  My next two used 3* are Iron Fist and Luke Cage (especially for PVP).  There are certain other 3*s that are good and very good but these four will really help you tremendously in PVE or, PVP if you play that too. 

     And in reference to not having to worry about roster slots 6 months down the road, I would have to disagree.  If you plan on spending a lot more money than I have on the game, then your slots issue may be less of an issue; but if you're an occasional spender or a free to play player, roster slots will probably be an issue for awhile.  Most of the people who have played before you, including myself, had vaulting in place that gave us a core of 3*s that we would get with every 3* or 4* pull, meaning we didn't have to devote all but a few roster slots for those vaulted characters.  Since vaulting is now gone, it'll most likely take a while longer to get a good stock of 3* top tier champs or get all of them rostered, if you want to do that.  So even six months later, I still make choices, almost daily, about which 4* covers I have to sell, because I don't have enough roster spots to keep them.

Do you have 1* characters still rostered? If so, you might look at them and see whether any space can be freed up (however caveat to that is the upcoming Apocalypse boss event where it seems 1* might be required, so would bear that in mind if applicable).

If you are short on roster spots, you could just rotate 2*s in and out during PvE events.  Just roster the 2* you need, and sell it when the next event starts.  However, you can't sell any of your 2*s while this is happening.  Being able to do the 2* nodes in PvE is much more important than selling your 2*s in inventory for isos.

You DEFINITELY want to start farming when you have available resources to do so.

This game is one-long endless farm.  Everything you do from the start will help you in the end.  The only exception is to roster a 5*.  You can speed it up with money, but it never ends until a player stops playing.