It is a particularly grey area. Reclining your seat is not readily obvious to the airline staff so there is no sort of umpire - instead, the law of the jungle applies and the struggle is carried on surreptitiously.
As with most tactical contests, it is best to move first. The starting place is, of course, the button on the left-hand arm of your chair - push it and throw your weight back hard enough and the seat jumps back, throwing anything on the tray table attached to it into the lap of the stout passenger behind.
You have to pretend that that was accidental.
The fact that he may have been annoying you with an over-loud eulogy about Donald Trump, generously larded with references to "Li'l ole Noo Zealand" not being big enough to appreciate him, must appear to be coincidence. Then, when he stands up and catches you by the shoulder, you can express surprise and regret about the seafood dish which now adorns his "Go Trump" sweater.
Provided you are careful not to smirk, he cannot do much immediately. If he throws a punch, the plane will be diverted to the nearest airport, probably somewhere in the Middle East, where he will spend several days with rats in the local slammer.
A perfectly good outcome from your point of view, of course, but, like a good chess player, you have to assume that this sort of quick victory is not available. No, he lurks biding his time until you are more or less asleep. Then a vicious kick into the back of the chair at kidney level and your nose hits the screen in front of you.
A drawled "sorry fella" in a Texan accent does nothing to restore your composure.
To get your own back requires cunning and, if you are an experienced traveller, you will have pretended to be lame and brought a walking stick by way of preparation.
Then all you need is for your adversary to remove his shoes and you can hook one quietly while the lights are off and throw it into the garbage at the end of the plane when you go to the loo.
A somewhat similar technique was used by John Malkovich in the film Dangerous Liaisons, but even an avid filmgoer is unlikely to spot the connection as he hops about on one foot while everyone else is getting down their luggage.
If you're in the middle of a row, it is much more difficult because inevitably there will be a moment in a flight of 17 hours when you need to visit the loo. At that point the lights will be off and the people next to you will be asleep under their rugs.
If you are impossibly athletic, you will simply vault into the aisle. For most of us, however, this isn't an option and the choice is between waking them up - not so good when you do it for the third time - or doing some judicious clambering.
It is here that your difficulties begin, because hidden under the rug is a mixture of chair arms (firm enough to take your weight), aircraft seat (ditto) and bodily parts (not ideal). That turns it all into a challenge. You have to prod the potential handholds and footholds and, once you have identified them, climb over the top. The key is to have a good look at your companions before they go to sleep so that you can get an idea of their general position.
There are some places where you had really better not put your hands and others, such as their tray tables and computers, where you can safely put a foot.
The difficulty comes if you get it wrong and they wake up halfway through the operation with a yelp of pain. There may be a fuss and a call for the steward. There is only one technique that will deal with this and it is the one we all use when we need to get out of crowded premises in a hurry. You clutch your throat and say:
"I'm terribly sorry, I'm about to be sick". As they recoil, you jump into the aisle. Then you spend the remaining 15 hours hiding in the loo.
-John Watson is the editor of the UK weekly online magazine The Shaw Sheet - www.shawsheet.com - where he writes as 'Chin Chin'.
