Determine all triples $(x, y,z)$ consisting of three distinct real numbers, that satisfy the following system of equations:
 $\begin {cases}x^2 + y^2 = -x + 3y + z \\
y^2 + z^2 = x + 3y - z \\
x^2 + z^2 = 2x + 2y - z \end {cases}$
Given the system of equations:
\[
\begin{cases}
x^2 + y^2 = -x + 3y + z \\
y^2 + z^2 = x + 3y - z \\
x^2 + z^2 = 2x + 2y - z 
\end{cases}
\]
We need to find all triples $(x, y, z)$ consisting of three distinct real numbers that satisfy these equations.

1. **Subtract the second equation from the first equation:**
\[
(x^2 + y^2) - (y^2 + z^2) = (-x + 3y + z) - (x + 3y - z)
\]
Simplify:
\[
x^2 - z^2 = -2x + 2z
\]
Factor both sides:
\[
(x + z)(x - z) = -2(x - z)
\]
Since $x \neq z$, we can divide both sides by $(x - z)$:
\[
x + z = -2
\]

2. **Subtract the third equation from the second equation:**
\[
(y^2 + z^2) - (x^2 + z^2) = (x + 3y - z) - (2x + 2y - z)
\]
Simplify:
\[
y^2 - x^2 = -x + y
\]
Factor both sides:
\[
(y + x)(y - x) = -x + y
\]
Since $y \neq x$, we can divide both sides by $(y - x)$:
\[
y + x = 1
\]

3. **Substitute $z = -2 - x$ and $y = 1 - x$ into the first equation:**
\[
x^2 + (1 - x)^2 = -x + 3(1 - x) + (-2 - x)
\]
Simplify:
\[
x^2 + 1 - 2x + x^2 = -x + 3 - 3x - 2 - x
\]
Combine like terms:
\[
2x^2 - 2x + 1 = -5x + 1
\]
Simplify further:
\[
2x^2 - 2x + 1 = -5x + 1
\]
Subtract 1 from both sides:
\[
2x^2 - 2x = -5x
\]
Combine like terms:
\[
2x^2 + 3x = 0
\]
Factor out $x$:
\[
x(2x + 3) = 0
\]
So, $x = 0$ or $x = -\frac{3}{2}$.

4. **Find corresponding $y$ and $z$ values:**
- If $x = 0$:
  \[
  y = 1 - 0 = 1, \quad z = -2 - 0 = -2
  \]
  So, one solution is $(0, 1, -2)$.

- If $x = -\frac{3}{2}$:
  \[
  y = 1 - \left(-\frac{3}{2}\right) = \frac{5}{2}, \quad z = -2 - \left(-\frac{3}{2}\right) = -\frac{1}{2}
  \]
  So, another solution is $\left(-\frac{3}{2}, \frac{5}{2}, -\frac{1}{2}\right)$.

Conclusion:
The solutions to the system of equations are:
\[
(0, 1, -2) \quad \text{and} \quad \left(-\frac{3}{2}, \frac{5}{2}, -\frac{1}{2}\right)
\]

The final answer is $\boxed{(0, 1, -2) \text{ and } \left(-\frac{3}{2}, \frac{5}{2}, -\frac{1}{2}\right)}$