Sorcerers are perhaps the most feared of presences on a battlefield, and rightly so, for they can wreak utter havoc with enemy forces, from enshrouding them in impenetrable mists to summoning demons or poisoned miasmas to destroy foes en masse.
Battle magic, it may surprise some, is not much different than standard sorcery—the scale is entirely different and such spells take far longer to cast as a result. This section will explain how to wield magic in mass combat.
Casting Battle Magic
Every aspect of a battle spell is larger, from the area of effect to the damage dealt, to the time it takes to cast the spell. In effect, a battle-version of a spell is a different spell than its man-scale version. Because of this, battle magic versions of spells must be prepared separately than the regular versions. Thus, just because a sorcerer has Sleep prepared for the day doesn’t mean he can use the battle version of the spell to drop a large unit of soldiers unconscious.
At the DM’s option, a sorcerer may be required to learn how to use battle magic, be it through learning specific battle magic spells, or being trained to adapt his existing spells for mass combat situations. This would make tomes of battle magic a coveted resource.
Of course, like all spells, magic wielded on the battlefield can only be cast upon targets within the sorcerer’s line of sight. This is why many sorcerers covet scrying items, such as crystal balls and magic mirrors, as such items allow sorcerers to ensorcel armies from safely within a stronghold or even miles away.
The act of casting a battle spell is identical to any other spell—the sorcerer rolls 2d6 against the target number for the spell’s difficulty (level) and either succeeds, fails, or suffers backlash.
The Scale of Battle Magic
In mass combat (resolved using Chainmail), spell damage is as listed in the OD&D books, but is inflicted on a 1:20 scale (mass combat uses figures, each figure representing twenty men). Thus, if a battle mage kills three figures with a cloudkill spell, he has in fact taken out sixty of his enemies’ troops. If a Hero or other specialized fantasy creature is currently attached to a unit that is destroyed, then he, she, or it will only be killed if enough damage is rolled to inflict a kill. Otherwise, note the damage suffered on the character’s sheet or monster’s statistics and move on (the same logic should apply when dealing with heroes engaged in melee: rather than being killed if a hero suffers four hits, for example, he will suffer 4d6 damage and if this kills him then he is dead; otherwise, he continues on, though wounded). The hero now acts alone (given a figure representing 1:1 scale in this case only) unless he moves to another unit and attaches himself there.
In man combat, one inch on the table top is equivalent to ten feet of distance. In mass combat, one inch is equivalent to ten yards. In man combat, a round is one minute. In mass combat, time is measured in ten-minute turns, including the time it takes to cast a spell. This makes battle magic largely impractical for personal (man scale) use—it requires ten to twenty minutes (depending on the result of a casting roll) to complete a spell.
Spell ranges, areas of effect, and duration for standard D&D spells can be found in the D&D supplement Swords & Spells, pp. 12-15. For new spells listed in this book, the range is always line of sight unless otherwise specified, and duration if listed in minutes or rounds becomes turns, while if listed in turns or hours remains as listed. Spells with casting times already listed in turns, hours, or tens of minutes remain as listed; otherwise the casting time is one to two turns depending on the result of the casting check.
Battle magic is strengthened by sacrifices just as normal magic is, and carries all the same associated dangers of corruption.