1. **State the problem:** We are given the expression $(N + 3)$ and need to understand any restrictions on the variable $N$. 2. **Identify the variable and expression:** The expression is a simple sum of $N$ and $3$. 3. **Check for restrictions:** Since this is a polynomial expression (a linear expression), there are no restrictions on $N$ from operations like division or roots. 4. **Conclusion:** The variable $N$ can be any real number. **Final answer:** $$N \in \mathbb{R}$$