WAM are a set of rules for battles based on common fantasy army types. From 2002 until now, they were only available in print form.
There will not be another print-run. However, fear not, they are now available in PDF form.
They use the Peter Pig original system of one-foot squares for the table layout. An oldie but a goodie, we think.
Below is a link to a page about how the rules work.
They cost £6.00 GBP.