Things to keep in mind when playing multiple PC's.

[Nuclear Catastrophe]

Any member of the playerbase can play multiple characters at any time.  And that's fine.  It's unenforceable for us, and most of the time unnecessary to worry about.

However, there are some inherent dangers when you're doing so.

You have to remember that what one character knows, the other does not.  Using information garnered using an 'alt' character on a different PC, to the original characters advantage, will probably get both of those PC's retired.

This is particularly pertinent to faction or subrace characters, who may well have natural enemies who they should not know anything about normally, but gain valuble information on them by being neutral or even allied with an alternative character .

If you have any questions related to this, feel free to ask any of your friendly neighbourhood DM team or even the playerbase at large.  
 
This doesn't mean that you should never play alt characters, this is just a general reminder that you have to be careful when doing so.  I think it's an important thing to keep in mind.