Returns a table of save values for an entity.
These tables are not the same between the client and the server, and different entities may have different fields.
You can get the list different fields an entity has by looking at it's source code ( the 2013 SDK can be found online, https://github.com/ValveSoftware/source-sdk-2013 ). Accessible fields are defined by each DEFINE_FIELD and DEFINE_KEYFIELD inside the DATADESC block.
Take the headcrab, for example:
For each DEFINE_FIELD, the save table will have a key with name of first argument.
For each DEFINE_KEYFIELD, the save table will have a key with name of the third argument.
See Entity:GetInternalVariable for only retrieving one key of the save table.
The value may be a sequential table (starting with 1) if the field in question is an array in engine.
Get how long it has been since the player was damaged
Determine if a door is locked (only works on server side otherwise returns nil)
DoorIsOpen( door ) that returns whether a door is open or not, for different door classes