One of the things that drew me to the genre of Sword & Sorcery early in my writing career was the gritty realism often exhibited in the stories I loved, something that was wholly different from the other genres of fantasy I was reading at the time. Now I love a good spell battle, fantastical creatures being used on the field, and wizards galore, but at the end of the day I truly think nothing beats two individuals (man or beast) meeting in some exotic and mysterious location to hammer it out to the bitter end.
There is an air of drama in combat shown with Sword & Sorcery that I think is desperately needs to be learned by writers if they are able to excite, in some cases disgust, and most importantly, depict action-oriented battle scenes and the reality of their effects. Currently I am working on a small pamphlet for some friends of mine in Charlotte Writers, a group I work for as the Head Organizer, which looks at writing combat from both my experiences as a martial artist in various disciplines (though I am always quick to mention that I am a master of none of them--not yet, at least, and even then...) It is still a few weeks away from being done, but I will publish it here when it is complete. Still, I believe there are things writers can do to get better acquainted with writing combat beyond joining the service or going out and participating in martial arts, and that is research!
I am going to include here a list of a few of my favorite books, placed in categories of Fighting, Combat, Effects and Outcomes:
Fighting: The Art of Moving
IAI: The Art of Drawing The Sword by Darrell Max Craig
Samurai Swordsmanship by Carl Long and Masayaki Shimabukro
Highland Broadsword by Christopher Scott Thompson
Highland Knife Fighting by Christopher Scott Thompson
Fighting with the German Longsword by Christian Tobler
Sigmund Ringeck's Knightly Arts Of Combat: Sword and Buckler Fighting, Wrestling, and Fighting in Armor by David Lindholm
The Way of the Warrior by Chris Crudelli
Pencak Silat Pertempuran: Vol. 1 by Sean Shark
Winning Wrestling Moves by Mark Mysnk
Mastering Jiu-Jitsu by Renzo Gracie
Combat: The Way of Fighting
On Combat: The Psychology and Physiology of Deadly Conflict in War and Peace by Dave Grossman - I should note that this selection might have appeared in the group below, but due to including another of this author's selections below, I placed it here.
Soldiers and Ghosts by J.E. Lendon - Truly one of my favorite books, especially since I focus on The middle to late Iron Ages in my settings.
Strategy: Second Revised Edition by B.H. Liddell Hart - This is truly awesome.
The Book of Five Rings by Miyamoto Musashi
The Art of War by Sun Tzu (Sawyer Translation)
Effects and Outcomes: The Cost of Both
Battlefield Angels: Saving Lives Under Enemy Fire by Scott McGaugh
Ancient Medicine by Vivian Nutton
Ditch Medicine: Advanced Field Procedures For Emergencies by Hugh Coffee
On Killing: The Psychological Cost of Learning to Kill in War and Society by Dave Grossman
These books are only a few of the sources I have used over the years, and I keep gathering new and reputable books over time as technology avails itself as a new window where martial artists, teachers, and researchers are gathering and presenting information into the digital age. One of the best sources for this is Youtube, where I found videos on Shastar Vidya and Pehlwani, which are the martial arts I used for The Vedic Sword & Sorcery novel that is nearing completion. You can find almost anything there to help you get a visual idea of martial arts and combatives you may want to use in your work.
I hope this has been helpful, and if you have any questions, criticisms, or concerns, by all means leave comment!
Thanks and stay safe!