The core concept of CLASH of spears was developed around a kernel of principles based on our understanding of personal combat derived from reading multiple sources over time, combined with the research most wargamers do from time to time and combined with our personal experiences resulting from years of competitive fencing.
However once you get past that kernel further research is required. It is necessary to find out details about the particulars of fighting style that go beyond what we’ve learned in the past from rules looking at large battles. This is because we really need to get to the specifics of how those styles of warfare would clash against each other once the melee is joined.
So it was obvious that we would need to do lots of additional research and the materials we used can be useful for new gamers to learn about ancients or for old wargamers to understand the support for our design decisions.
We started with the classics: Connelly, Goldsworthy, Warry… These help set the period and organize general concepts.
Nest we moved to more detailed tactical break downs, Legion vs Phalanx and Greek & Roman Warfare provide great understanding of the main styles of combat and A Storm of Spears is a fantastic in detail analysis of hoplite combat techniques.
Even then further details is sometimes needed to characterize some of the nations not generally covered as the main subject in other books and here is were this fantastic publication Ancient Warfare Magazine kicks in.
This has been a fundamental research source for as as the detail reach on each article is astounding
To give our readers a good summary of some issues that they can consult depending on the forces they are building here you have a useful list:
( note that you can acquired those both in printed form or in pdf so it is a great source to expand your knowledge on the period ).
Italian Tribes: Vol XI, issue 2 , Vol IV, issue 1
Samnite Wars, Vol VII, issue 2
Spanish tribes: Vol I, issue 4
Pyrrhus, Vol XIII, issue 1
Hannibal in Italy Vol III, issue 4
First Punic War Vol IX, issue 4
Greek Warfare Vol IX, issue 5 , Vol V issue 6
War in Sicily Vol VII, issue 2
Marian reforms, Vol V, issue 1
Finally to get fun ideas for scenarios some fictionalized historical novels are always fun … here you have some that I liked,
Darkness over Cannae, awesome graphic novel
Hannibal Enemy of Rome
The Ghosts of Cannae
Of course there is plenty of other material but these are excellent sources and will help you understand the reasons behind most of the rules in CLASH.