Free Mortal Engines by Stanislaw Lem

art. His kingdom swarmed with thinking machines, for Poleander put them everywhere he could; not merely in the astronomical observatories or the schools, but he ordered electric brains mounted in the rocks upon the roads, which with loud voices cautioned pedestrians against tripping; also in posts, in walls, in trees, so that one could ask directions anywhere when lost; he stuck them onto clouds, so they could announce the rain in advance, he added them to the hills and valleys—in short, it was impossible to walk on Cyberia without bumping into an intelligent machine. The planet was beautiful, since the King not only gave decrees for the cybernetic perfecting of that which had long been in existence, but he introduced by law entirely new orders of things. Thus for example in his kingdom were manufactured cyberbeetles and buzzing cyberbees, and even cyberflies—these would be seized by mechanical spiders when they grew too numerous. On the planet cyberbosks of cybergorse rustled in the wind, cybercalliopes and cyberviols sang—but besides these civilian devices there were twice as many military, for the King was most bellicose. In his palace vaults he had a strategic computer, a machine of uncommon mettle; he had smaller ones also, and divisions of cybersaries, enormous cybermatics and a whole arsenal of every other kind of weapon, including powder. There was only this one problem, and it troubled him greatly, namely, that he had not a single adversary or enemy and no one in any way wished to invade his land, and thereby provide him with the opportunity to demonstrate his kingly and terrifying courage, his tactical genius, not to mention the simply extraordinary effectiveness of his cybernetic weaponry. In the absence of genuine enemies and aggressors the King had his engineers build artificial ones, and against these he did battle, and always won. However inasmuch as the battles and campaigns were genuinely dreadful, the populace suffered no little injury from them. The subjects murmured when all too many cyberfoes had destroyed their settlements and towns, when the synthetic enemy poured liquid fire upon them; they even dared voice their discontent when the King himself, issuing forth as their deliverer and vanquishing the artificial foe, in the course of the victorious attacks laid waste to everything that stood in his path. They grumbled even then, the ingrates, though the thing was done on their behalf.
    Until the King wearied of the war games on the planet and decided to raise his sights. Now it was cosmic wars and sallies that he dreamed of. His planet had a large Moon, entirely desolate and wild; the King laid heavy taxes upon his subjects, to obtain the funds needed to build whole armies on that Moon and have there a new theater of war. And the subjects were more than happy to pay, figuring that King Poleander would now no longer deliver them with his cybermatics, nor test the strength of his arms upon their homes and heads. And so the royal engineers built on the Moon a splendid computer, which in turn was to create all manner of troops and self-firing gunnery. The King lost no time in testing the machine’s prowess this way and that; at one point he ordered it—by telegraph—to execute a volt-vault electrosault: for he wanted to see if it was true, what his engineers had told him, that that machine could do anything. If it can do anything, he thought, then let it do a flip. However the text of the telegram underwent a slight distortion and the machine received the order that it was to execute not an electrosault, but an electrosaur—and this it carried out as best it could.
    Meanwhile the King conducted one more campaign, liberating some provinces of his realm seized by cyberknechts; he completely forgot about the order given the computer on the Moon, then suddenly giant boulders came hurtling down from there; the King was astounded, for one even fell on the wing of the palace and destroyed his prize