function wesnoth.wml_actions.check_unit_in_range(cfg)
    local primary_suf = helper.get_child(cfg, "filter") or
        helper.wml_error "[check_unit_in_range] missing required [filter] tag"
    local second_suf = helper.get_child(cfg, "filter_second") or
        helper.wml_error "[check_unit_in_range] missing required [filter_second] tag"
    local variable = cfg.variable

    if variable == nil then
        variable = "in_range"
    end

    local u1 = wesnoth.get_units(primary_suf) or
        helper.wml_error "[check_unit_in_range] could not match primary unit"
    local u2 = wesnoth.get_units(secondary_suf) or
        helper.wml_error "[check_unit_in_range] could not match secondary unit"

    if helper.distance_between(u1.x, u1.y, u2.x, u2.y) <= u1.max_moves then
        wesnoth.set_variable(variable, true)
    else
        wesnoth.set_variable(variable, false)
    end
end