Across the war-torn field of battle, the powerful alicorns faced each other. The two ancient sisters who were once allies, now become bitter foes; their evenly-matched forces arrayed to take every possible advantage of the terrain that separated them. They had battled long and hard, and both had seen many troops fall in this senseless conflict. But reason had failed, negotiations broken down, every attempt at compromise come to naught. Now all that remained for them was the brutal diplomacy of steel and blood. This would be their final battle, all would be decided here, and now.
"Thy tyranny ends today, Tia!" Luna cried out in her best Royal Canterlot Voice. "Mine forces shall sweep through the wretched remnants of thine ineffectual army and storm the castle battlements unopposed! We shall roll over thee like the inexorable tide, and thou shalt be washed away! The Solar Empire falls today!" A mighty cheer rose up from the massed troops of Luna's army.
Celestia did not match Luna's bombast; her forces were too worn down from the prolonged campaign, and she herself too battle-weary to do much more than glare. She had weathered too many setbacks and defeats to marshal a suitable challenge to her sister's rhetoric, choosing instead to simply mutter, "We shall see, my sister; we shall see." The sun princess had prepared her forces for an epic frontal charge, a violent clash of body against body, blade against blade. Her opponent had gathered her own forces too closely, clustering them tightly together behind the unscalable Phoenix Fire Mountains where they were immobilized and vulnerable. Celestia's infantry stood along the coast of the Sunset Sea, ready to engage the bulk of Luna's army, while a flanking charge by her unicorn cavalry across the Frostflower Plains, supported by her remaining battle mages, would leave the opposition nowhere to flee, penned up between the mountains and the coastline. Luna's forces would be crushed between Celestia' cavalry on one side, and her infantry on the other — a classic hammer-and-anvil tactic — and she could pick off any survivors at her leisure. At long last, the battle would be hers. She commenced her charge, victory in sight.
But alas, 'twas not to be. With a sudden flash, she witnessed her meticulously-drafted plans unravel. What she had thought a mere scouting unit delivered an unexpected and devastating blow. She watched as the moon princess sacrificed her three strongest mages and the small unit that guarded them to set off a magic flare of unprecedented size and power. It ravaged the northern reaches of the Frostflower Plains, engulfing Celestia's charging cavalry, overwhelming and stunning them. Luna's own troops remained protected from the flare, shielded behind the mountain where Celestia had thought them pinned. Too late she saw the trap her sister had set. With no troops to meet the counter-charge that was surely to follow, she saw her victory slip away like water through her hooves. The two units of Luna's elite Chiropteran Guard flew up and over the mountain, descending like lightning into the midst of her incapacitated unicorns. Although they outnumbered Luna's Guard by more than three to one, the cavalry were defenseless against the onslaught soon to follow. They would be slaughtered to a pony, and their princess had no way to save them.
Around the other side of the mountain the remainder of Luna's forces swept; the point of their wedge thrusting deep into the front lines of Celestia's now-outnumbered earth-pony infantry. Luna raised her head, a look of vindication on her face. "And now, my sister, the reckoning has come! Thou seest thy doom before thee!" Luna grasped a large pile of dice in her magical aura, and cast them upon the table that stood between the clashing princesses. "Six sixes, eight fives, and three fours. Ha! And you get no saves this round!" Celestia dutifully removed nearly two thirds of her unicorn cavalry figures from the table. Luna picked up the dice, adding half again their number more. "Now for thine infantry!" She again cast the dice upon the table. "Five sixes, nine fives, four fours, and seven threes. Add the plus one from charging, and thou art righteously smited!"
Celestia sighed, seeing over a third of her infantry destroyed, leaving the rest outnumbered over two-to-one by Luna's combined forces, with the Chiropteran Guard still available to threaten her rear. The tide of battle had turned against her, and she knew she had no chance of rallying. She could see defeat looming inexorably before her.
"That was a cheese move, Lulu. Pure cheese."
"So what! 'Tis perfectly legal, and it worked beautifully! Doest thou want to play out the rest of the combat?"
"No, it's obviously a foregone conclusion at this point. I concede."
"Ha! Another glorious victory for the New Lunar Republic! Up your face!" Another cheer went up from Luna's army, and a victory march began to play.
Celestia raised a hoof to her face and sighed as her sister did a little dance on the opposite side of the table. "In."
"Hah! what?"
"The phrase is 'In your face', Lulu. 'In', not 'up'."
"In your face! Now thou hast to arbitrate the Griffon-Minotaur mineral rights dispute, and I get to judge the Canterlot Academy annual pie bake-off! Ha ha!"
"Yes, yes, I know. That was the agreement. The winner gets the pie, the loser gets the trade negotiations." Another sigh. "You always were the better tactician, I'll give you that. Why I let you talk me into this game..." Celestia mumbled almost to herself, ears drooping sideways. "But for Harmony's sake Lulu, do you have to make the sound effects every single time?"
"Well, what poor amusement would there be if I did not? Especially the triumphant victory song at the end. 'Tis my favorite part!" Luna hummed the new tune she had composed to celebrate her triumph (in advance, of course), while she carefully packed her exquisitely-painted toy soldiers and siege engines into their carrying cases, before prancing out of the war room and down towards the student's hall.
Celestia sighed yet again. Next year. She would spend that entire time brushing up on her tactics and game rules, maybe get Spitfire to give her some pointers; and next year she would win for a change. Thinking about it, she could almost taste the pies.