In British-English slang, the imperative phrase sod (also bugger, fuck, etc.) this for a game of soldiers expresses exasperation at a situation or course of action, typically with the implication that the speaker intends to leave or give up.

This phrase occurs, for example, in A new start after 60: I found love after a painful divorce—and we moved to an uninhabited island, by Emma Beddington, published in The Guardian (London and Manchester, England) of Monday 3^rd April 2023:
—Context: When John King met his partner Lynn, “she opened up a spiritual path that led to three years off-grid in the beauty of the Inner Hebrides”:

King would transport fuel by boat and quad bike to the cottage several times a year. “The first December, it was about -6C and I remember spending a day in wet snow bringing in half a ton of coal and thinking: ‘Bugger this for a game of soldiers!’”

The text containing the earliest occurrence of sod (also bugger, fuck, etc.) this for a game of soldiers seems to indicate that this phrase originated in military slang during the Second World War.

What game of soldiers refers to in this phrase (though much debated) remains unclear.

The earliest occurrences of the phrase sod (also bugger, fuck, etc.) this for a game of soldiers that I have found are as follows, in chronological order:

1-: From Through the dark night: Being some account of a War Correspondent’s journeys, meetings and what was said to him, in France, Britain, and Flanders during 1939-1940 (London: Victor Gollancz Limited, 1941), by the British novelist, scriptwriter and journalist James Lansdale Hodson (1891-1956):

In the middle of a very hot mixed-up fight one of our men remarked drily on his radio, “What price this for a game of soldiers!”

2-: From Forging the Link: A Handbook of Hashomer Hatzair in England and Israel (London: Hashomer Hatzair, 1952):

A cold gust of wind fans your face, you shiver slightly, you have been standing still, “get moving,” you say to yourself, only another hour to do, the rifle is heavy, brrrr, blow this for a game of soldiers, they have no consideration at all.

3-: From The Long and the Short and the Tall (London: Penguin Books Limited, 1962), by the British playwright Willis Hall (1929-2005):

It’s a crumb patrol. It’s just about the crummiest detail in the Far East is this, and no messing. Two days humping kit and two days back! Routine Patrol! You can stick this for a game of soldiers. Talk about the P.B.I. If ever there was an all-time crumb patrol, we’re on it.

4-: From Terms of Reference (London: Hutchinson, 1966), by the British novelist Stanley Middleton (1919-2009):

‘I’ll do your share,’ Robert said. They had eaten a man’s tea, thick sandwiches, hunks of cake, together.
‘You start the ball rolling,’ Jake said.
‘Damn that for a game of soldiers. You’re the one . . .’
‘No,’ Jake said.

5-: From Cockade (New York: Grove Press, Inc., 1967), by the British playwright Charles Wood (1932-2020):

Dickie Bird: And I could. No—to be strictly factual there’s only one thing I’m sweating on …
Harry: You’re sweating on him stopping …
Garibaldi: Get some in.
Dickie Bird: And that for a game of soldiers—I’d be back in that box with the instructions ’fore you can say F.F.I.
Garibaldi: That’s your sweat.
Dickie Bird: Don’t come to me Jack. I’ll be too busy sorting out rations.

6-: From Country Matters (London: André Deutsch Limited, 1971), by the British author and broadcaster Fred Basnett (1928-2006):

He’d set us up as the diversion but hadn’t thought it necessary to explain where we fitted in his grand strategy. Well sod that for a game of soldiers, I wasn’t playing any more. The other two didn’t even notice they’d been conned.

7-: From Hat (London: Tom Stacey Limited, 1971), by John Brooks:

‘That’s bloody silly talk.’
‘Sod this for a game of soldiers.’
The platoon commander had taken off his smock and lain down on his groundsheet again. He remembered that at the Battle of Hastings William the Conqueror had put his lorica on the wrong way round.

8-: From It’s really a question of confidence…, by Peter Wilkin, published in the Bury Free Press (Bury St Edmunds, Suffolk, England) of Friday 29^th November 1974:

Actually it was when I was mentally concocting a headline-snatching article about going fishing 50 times without a bite and making history in the Guinness Book of Records, that I finally realised that I had given in and did not expect to catch a fish.
The shock of this realisation made me think—to hell with this for a game of soldiers—and I packed my gear with a new sense of urgency. I found a new swim in a different pit and got absolutely drenched in the move. I tackled up again and set about catching one, just one, wretched fish.

9-: From Robinson Crusoe Smith, by John Smith, published in the Sunday People (London, England) of Sunday 23^rd November 1975:
—Context: The author is writing from the Juan Fernandez Islands, off the coast of Chile; “Man Friday” is “actually a fisherman called Willy”:

I was all for doing a marooned mariner bit, and spending the night in Alexander Selkirk’s cave. But Man Friday muttered the Spanish equivalent of “Maracas to that for a game of soldiers,” and I settled for a room in a tiny inn.

10-: From the review of a pantomime which appeared in dialogue form in the magazine Melody Maker—review from the column People Talk, edited by Mervyn Pamment, published in the Sunday People (London, England) of Sunday 24^th December 1978:

The panto stars God, Jesus and dead rock singers who have gone to Heaven—Elvis Presley, Janis Joplin and Jimi Hendrix.
God is an Alf Garnett-type character who swears a lot, offering Elvis, for instance, “a kick in the side of the — head” and talks of his — yacht off — Cannes.
Jesus, who is presented as a raving gay, is also given to swearing with such originals as “— that for a game of soldiers.”