Yes, in the RV world a converter takes 120vAC wall power and converts it into 13.6vDC for powering 12v loads and charging batteries.
An Inverter takes battery power and makes household electricity, albeit inefficiently.
YOur RV might already have both an inverter and a Converter. The inverter might have to be switched on manually for your existing outlets to work. There is no way for any of us to say.
For your laptop you could run a DC to DC 'car adapter' instead of an inverter. Plug your laptop make and model into amazon electronics and add car adapter. These are more efficient than running an inverter.
The son;s game thing, does it recharge via a USB plug?
If so, then one of these is all you need for that:
http://www.amazon.com/s/ref=nb_sb_s...ds=usb+car+charger&sprefix=usb,automotive,200
A small inverter could power both. Laptops tend to max out at 120 watts these days, so a small inverter could be used:
http://www.amazon.com/s/ref=nb_sb_n...tt+inverter&rh=n:15684181,k:250+watt+inverter
Please note than at 60 watts or more, ciggy plugs and receptacles become problematic, or will become so at some point. Hooking the inverter right to the battery will achieve its full wattage.
The USB charger ciggy plugs are OK as they rarely pass more than 20 watts.
Please note it is easy to deplete a battery with an inverter powering things one brings from a stick and brick house.
My laptop can consume upto 7AH per hour, and I only have ~45 AH to use before my battery hits 50%.