import Foundation
import SpriteKit

class War: SKScene {

static var sharedWar = War(size.size)
...

}

- (void)save {
    [[NSUserDefaults standardUserDefaults] setObject:@{@"x" : @(self.x), @"y" : @(self.y)} forKey:@"WarKey"];
    [[NSUserDefaults standardUserDefaults] synchronize];
}

- (void)load {
    NSDictionary *data = [[NSUserDefaults standardUserDefaults] objectForKey:@"WarKey"];
    if (data == nil) {
        self.x = DEFAULT_X;
        self.y = DEFAULT_Y;
    } else {
        self.x = [data[@"x"] intValue];
        self.y = [data[@"y"] intValue];
    }
}