user13744: 
My move was Kxc3. The move was labeled as a blunder. Why?

user12449: Simply put, Kxc3 loses a piece or the exchange after Rc8.

[fen "1n3rk1/5pp1/4p2p/8/q1N1QP2/Pnp4P/1PK2PP1/3R1R2 w - - 0 0"]

1. Kxc3 Rc8 2. Rd6 {or any move} Na5 3. Rd4 Qb3+ 4. Kd2 Nxc4+



13744: <p><img src="https://i.stack.imgur.com/XMjy2.png" alt="enter image description here"></p>

<p>My move was Kxc3. The move was labeled as a blunder. Why?</p>
 12449: <p>Simply put, Kxc3 loses a piece or the exchange after Rc8.</p>

<pre><code>
[fen "1n3rk1/5pp1/4p2p/8/q1N1QP2/Pnp4P/1PK2PP1/3R1R2 w - - 0 0"]

1. Kxc3 Rc8 2. Rd6 {or any move} Na5 3. Rd4 Qb3+ 4. Kd2 Nxc4+

</code></pre>
