private void addSpeed(Effect e, boolean positive) {
		int x = positive ? 1 : -1;
		if (e.getStat().equals("speed")) { // TODO remove magic
			PlayerPhysics physics = ((PlayerPhysics) components
					.get(ComponentType.PHYSICS));
			physics.setSpeed(physics.getSpeed() + e.getBoost() * x);
		} else if (e.getStat().equals("runSpeed")) {
			PlayerPhysics physics = ((PlayerPhysics) components
					.get(ComponentType.PHYSICS));
			physics.setRunSpeed(physics.getRunSpeed() + e.getBoost() * x);
		}
	}