Giant Fighting Campaign

Rules and Physics for large creature fighting are pretty challenging. One of the reasons one would like to play such a campaign is to kill big monsters, but for me it would be what would combat doctrine be like at such sizes.

Shinjeki no Kyojin is an inspiration to this, but I believe you can achieve heroic and dramatic Feats as well as visually stunning scenes even with the science and physics still intact. Although to be true to the Inspration, i want to have a game with a good number of fatalities. My first programming learning project is a character generator (spitting out characters).

Here are the Giants I contributed in GURPS . I tried following the square cubed rule when it came to sizes. These giants have huge bellies that allow them to extend their range as they forage.  

I'd use gurps but modified with 6 second rounds instead of second by second. DnD would work also, and even Mgt traveller system but it has to be made more elaborate. Many low tech fantasy systems come to mind that can run this, but they need a lot of work. If it were me and Gurps it would be probably 40 hours of prep with maps and tokens eating up 90% since I already did most of the research on size scaling in gurps.

The world builder has to establish an ecological and biological reason how such huge creatures exists. Drawing up studies on elephants would be the first order of business. Then he proceeds to figure out how man fits in this complicated picture. A lot of eureka moments just doing that, and unfortunately not much appreciation.

Naturaly this would have Acrobatic Combat, and this would be fun. If you've seen whirling Wuxia spear fighting (that can be used as a Pole) with Acrobatics, and pretty much Post Apoc and Alien Dynamic Terrain, this would be epic!

Maybe some Post Fall Pharmacy have special drugs for healing and muscle strength, and special conditioning for altered human forms (Heavier or Lighter). 

Sample Campaign

• A colony lost in an Interstellar Dark Age, fortunately humans have adapted to the environment so much and its been "terra-formed" to meet half way that it is as bio-diverse and growing as Terra. Aesthetically a bit different, but the biology and physics allow for a bit of fantasty creatures. 
• Barely Industrial Revolution level of technology. Food is plentiful, birth rates are much higher than medieval and medicine. Its like China in pre-industrial levels 500Million in 3.7 million square kilometers (roughly the size of the US).    
• Other than Giant Trees, that create a city like landscape, there are Canyon systems as well. I would draw from Yellow Mountains in China as well (one of the terrain inspirations in Dragon Ball and many China inspired martial arts movies, the pillar like mountains is different) as well as those found in Africa. 
• Human settlements are on these special terrains (giant trees and canyon or mountains) where water is available and many industrial earth movers and water works allow for sheltered farming. Some of the terrain is still accessible normally, but are guarded with walls and holdfasts. 
• Giants are of the 3-5m variety. see giants templates above. The Giants have ranging endurance of about the same as an elephant typically 20km or 15miles a day when foraging but when pushed to extremes can cover up to 80km per day. When they organize for marches, they can cover 30km consistently daily (it is whittled down by terrain modifiers, but they can overcome most terrain because of sheer size). 
• Carniverous, they will eat the all the dead (sans armor and metals spitting them out or working around them the way a human would with seeded fruit). They can pretty much store enough meat in their belly for a week of travel without need for foraging. They can basically make foraging roles everyday at a penalty relative to their fast pace. 
• Humans have limited access to gunpowder. The most common weapon are SPEARS and Pole-arms when fighting giants, and most tactics and doctrine is about maneuverability instead of armor. Parkour or Acrobatics and a lot of Running is part of the training of the defensive militia. 
• There are a lot of cavalry using exotic mounts: deer-like, goat-like, bull-like, flightless bird-like, and some horse-like cavalry. The most common type is a Lamma-like pack animal that has stats similar to a mule with poor gait but can 
• Acrobatics, Running, Hiking, and Logistics are key skills humans have that allow them to fight these Giants. Logistics can be sophisticated with secret caches of supplies left over by ranging parties. Human's Endurance advantage is important and is augmented by logistics. 
• Combat system has to be adapted to the 6 second one because most of combat is maneuvering instead of attacking. 
• Mysteries on mysteries on mysteries...  
• Players can be part of armies trying to established secure trade routes or merchant retainers trying to protect trade and assets, or the defense force of an isolated city state under siege. They can be scouts searching for other survivors and lost technology.