Rock paper scissors OOP approach

gistfile1.php

<?php

class DrawException extends DomainException {}

abstract class Hand {

	public function beats(Hand $hand) {

		$this->rejectDraw($hand);
		$this->assess($hand);
	}

	protected abstract function assess(Hand $hand);

	public function __toString() {
		
		return get_class($this);
	}

	public function rejectDraw(Hand $hand) {

		if ($hand === $this) {
			throw new DrawException('No player wins, round is a draw');
		}
	}
}

interface Wrappable {}
interface Cuttable {}
interface Bluntable {}

class Rock extends Hand implements Wrappable {

	protected function assess(Hand $hand) {
		
		return $hand instanceof Bluntable;
	}
}

class Paper extends Hand implements Cuttable {

	protected function assess(Hand $hand) {
		
		return $hand instanceof Wrappable;
	}
}

class Scissors extends Hand implements Bluntable {

	protected function assess(Hand $hand) {
		
		return $hand instanceof Cuttable;
	}
}

$hands = ['r' => new Rock, 'p' => new Paper, 's' => new Scissors];

echo "Choose hand [r, p, s]: ";

$choices = [
	'computer' => array_keys($hands)[rand(0, 2)],
	'player' => strtolower(trim(fgets(STDIN)))
];

$computerHand = $hands[$choices['computer']];
$playerHand = $hands[$choices['player']];

echo "Player chose $playerHand\n";
echo "Computer chose $computerHand\n";

try {
	if ($playerHand->beats($computerHand)) {
		echo sprintf("Player wins, %s beats %s\n", $playerHand, $computerHand);
	} else {
		echo sprintf("Computer wins, %s beats %s\n", $computerHand, $playerHand);
	}
} catch (DrawException $ex) {
	echo $ex->getMessage() . "\n";
}