Surely there's no way of getting that usual classic Mars/Barsoom style feel with Castles & Crusades?! Right well no there is actually. The dungeon master can use a little book that takes several systems for combining & using classes as need in the Siege System. I'm talking about C&C's Expanding Classes here & its a very different set of systems then the usual AD&D & D20 multiclassing, enhanced classes and switching classes.
Here the systems are used in a very solid way, Alexander L. does a fantastic job taking on the character class options from C&C's Expanding Classes book ;
:So let’s talk about the five options that you have here in Expanding Classes:
1) Multi-Classing. This is where, instead of having a single class, say Fighter or Cleric, you have two classes like Ranger/Druid or Assassin/Bard. There’s a nice little cross-reference chart so you can see which of the thirteen classes can multi-class together. This means you can’t do a Paladin/Assassin or Barbarian/Wizard, but there is always wiggle room if you have a good reason and a willing Castle Keeper. The downside to multi-classing if you advance a lot slower as you have two classes you are trying to level up, and some classes may have weapon/armor/spell restrictions that hinder your second class. Essentially this is the same as old school AD&D multi-classing
2) Enhanced Class. This is essentially an “enhanced” and deeper version of the “Class and a half” idea that is briefly mentioned in the PHB after multi-classing. Again, there is less than a page for this there. With Expanding Classes, you get a lot more detail and depth on the topic. An Enhanced class gives you a few aspects of a second class, but not all of them. This is great if you have a character who say, went to Wizard school but flunked out and has a little to show for his time spent there. There are over two dozen supporting class options, and again, a chart to cross reference so you can see if your idea is legal or not. Each of these supporting classes has its own XP chart to show you what you get at each level. Essentially your cost to level up your supporting class is only half of what a full class would cost, but you only get a fraction of the abilities and advance much slower.
3) Class Plus. This adds the zero level abilities from another class to your character for a permanent 5% tithe of all experienced earned. That may or may not be worth it to you, as at higher levels, that is a lot of experience to give up just to have access to cantrips or 1d3 unarmed Monk attacks but hey, more power to you if you want to go this route. Class Plus is the weakest of the options in Expanding Classes and I doubt many will make use of it. Hell, even Troll Lord Games doesn’t put much stock in it, giving the idea less than half a page in this supplement.
4) Dual Classing. This is very different from the AD&D version of Dual Classing. A character is a single class until some pivotal moment in their adventuring career and then they decide to switch completely to another class. Maybe they were a Barbarian who found God and became a cleric. Maybe they were a Ranger but went blind and decided to become a Diviner instead since they couldn’t track anymore. There are lots of reasons why a second class might be added later in life instead of starting off via multi-classing. Once the second class is chosen, XP is evenly divided between the two and you level up as usual. The catch is that the character only gets new Hit Points when it gains a level in its original class. This doesn’t sound or seem too bad unless you are really high level. After all, if you are a level 16 Fighter/Level 1 Bard, you will have a ways to go before you see an increase in your HP. At least you’ll get some spells and Legend Lore out of it!
5) Reclassing. This is where a character abandons their original class completely and takes up something new. OD&D fans will recognize that this is the TSR version of Dual Classing and Troll Lord is simply calling it “reclassing” for Castles & Crusades since they are using Dual Classing in a different fashion. It’s not an exact port from AD&D to C&C as you lose a level (and HD) for doing this but otherwise, it’s similar down to the 10% XP penalty for using skills/abilities from the previous class in an adventure. Although the name change may confuse or annoy older games, calling this Reclassing actually does make more sense than calling it Dual Classing., so I’m fine with it." So I'm I fine with it & you can read more at Alex Lucard's article here.
What kinda Mars I'm I going for?! The type where mankind has fled Earth & is on the run in the solar system. Hyperborea has appeared in the skies of Earth along with a giant Saturn & Jupiter has become its own sun. Alien life forms have appeared thanks to Clark Ashton Smith's The Dweller In The Gulf & its twin Vulthoom . Mankind has no idea of the depths of Martian Hell that it might find itself in. In fact what I'm looking at for inspiration right now is a short story published in September 1951 issue of Planet Stories magazine by D. B. Lewis called Vengeance on Mars as adventure inspiration. “Vengeance on Mars,” a short Sci-Fi story penned by Jerome Bixby under the pseudonym D. B. Lewis.
"In the dim Water Temple, where the dead grinned down on the dead, Hale met his D-day. Should he give an ex-comrade to the torturing Lhrai or chance the massacre of Terrestrial thousands?"
Many of the systems (but not all) that are in the C&C's Expanding Classes book would later on be incorporated into the Amazing Adventures! rpg Companion. But what about Astonishing Swordmen & Sorcerer's of Hyperboreans?! Are they on Mars in this campaign?! The answers are coming up tomorrow.