Invoking a method on a nil pointer in iOS can lead to unexpected crashes. Think of it like trying to play a game of Pips NYT with missing pieces – things are bound to fall apart. Your app will likely terminate with a signal like EXC_BAD_ACCESS, since you're essentially trying to access memory that doesn't exist. Careful coding practices are key to avoid this.

Hi msn games, The program continues running normally.

A message sent to a nil object is perfectly acceptable in Objective-C, it's treated as a no-op. There is no way to flag it as an error because it's not an error, in fact it can be a very useful feature of the language.

It returns 0, nil, a structure filled with 0s, etc.