Pick up almost any wargames publication that mentions Boxers, and you'll be introduced to a bunch of fanatical technophobes. One-trick ponies, they'll charge and be shot down in droves.
But was it really that simple?
I won't try to rehash the roots of Boxer phenomenon. Others have done it far better that I could - and using original sources. What I want to examine is how they fought when they fought. This is a wargamer's blog after all. Much of what follows is guesswork, built upon hints from secondary sources, and piled upon peripheral knowledge of group dynamics. It it not original research, merely applied supposition.
Western sources frequently referred to the fanatical charges of Boxer groups. We are left to infer that they were also quite adept at setting ambushes given their ability to catch guards napping. They also fully understand the idea of cutting rail lines in front of and behind a train, isolating it and destroying water tanks, further limiting the movement of trains. Clearly they have the skills of the partisan, at the very least. This should not be surprising when you recall the other rebellions that had taken place in and around Shantung (Shandong) province where they originated - the Taiping and Nien to mention two recent ones.
However it is probably more complex than that, simply because I believe that the "Boxers" changed shape over the two or three years of their existence.
Early Phase - an agrarian protest against discrimination in favour of Christians. This phase has law-abiding farmers and landowners hitting back against Christian groups who stood outside the normal law because of the Unequal Treaties, with bandits taking up christianity (small "c") in order to avoid Chinese justice. Weapons were probably very basic, and any firearms would likely be limited to a scattering of old matchlocks. More likely to be guerrilla raids and property burnings rather than standup fights, but largely limited to melee weapons.
Rising Tide Phase - all of the above, but starting to grow and becoming better-organised. This phase has Boxers attacking symbols of western culture (missionaries and railways) and facing persecution from government in some regions. This phase also sees mysticism taking over - the "boxing" plus other buddhist ritualism. Now the movement is pulling in the unemployed and the hungry - the people most desperate for a cause or a meaning. Some will have been veterans of the Sino-Japanese War, or victims of cutbacks in the Green Standard forces, so would have had some basic military training and maybe even some better firearms - breechloaders perhaps. Ammunition may have been a problem, but some could be acquired from defeated regulars, friendly magistrates, or western gunrunners. This also covers the first week of Seymour's expedition - up to the allied attack on the Taku forts.
High Water Phase - This is where the government finally throws its lot in with the Boxer "militia", repulsing Seymour's expedition and besieging the foreign settlements at Tientsin and the Peking legations. Here we see many more firearms being distributed to (or picked up by) the Boxers. We also hear of fewer fanatical charges as mysticism loosens its hold - probably as the effect of bullets becomes obvious. The fall of Tienstin seems to have been the death-knell for the movement in the countryside of Chihli (Zhili) province, with little mention of Boxers during the subsequent advance to Peking. They are still active in Peking itself, but their last gasp is when they are driven from around the Peitang Cathedral on 16th June. They may still be active after this date in Manchuria, but as an embodied militia.
Ebb Tide Phase - After the fall of Peking the life has gone out of the movement. Partly because it's simply so dangerous, with punitive expeditions fanning out from Peking, but also because the rains arrive, after a 2-year drought, watering the fields that now need the agricultural labour that had been idle for so long. That doesn't stop the international forces (especially the Germans and the Russians, according to English language sources) executing Boxers in every village they enter. But others lament that many innocents are slaughtered for every one that may actually have been a Boxer.
Anyway that's my interpretation. If I ever get round to reflecting Boxers on a wargames table they will look something like this:
Early Phase - small actions only. Few firearms.
Rising Tide Phase - willing to charge into contact, but with a scattering of firearms throughout.
High Water Phase - many more firearms, and much less reluctant to charge home
Ebb Tide Phase - small actions only. Snipers with firearms, but otherwise demoralised