Real Consequences of breaking lease?

[Donald S.]

Hi all, 

I'll be closing my first rental soon and wanted some clarification. If a tenant moves out, with or without notification, prior to their lease being over what consequences do they really face? 

What can I do to recoup losses? 

Is it legal to withhold the security deposit even if there's no "damage" to repair with it?

Do people tend to file a small claims against them for the balance that would have been due through the end of their lease? 

What other remedies or options would I as a new landlord have? 

I hope I won't have to deal with this, but things happen and I'd like to be prepared just in case. If it matters the property is in the St. Louis MO, in the city. 

Thanks

Cheers!