http://kschnee.xepher.net/code/unit.....le_system.html -- Go here to play!

Here's a playable demo of a simple battle system. It's inspired by the card games "Ninja Burger", "Space Pirate Amazon Ninja Catgirls", and "Buck: Legacy", and the tabletop RPG system "Fate". Instructions:

One of two scenarios will randomly appear when you load the demo: a battle to the death with evil changelings (sorry, Thorax) or a high-stakes baking contest. Hit Reset if you want to try the other one. Each of these challenges has steps that you resolve with a die roll: Skill+2d6 >= difficulty. Each turn, each character can "Strike" (try to solve a challenge step), "Help" (aid an ally), or "Rest" (do nothing). Defeat all steps to win!

The "Help" action forfeits your turn, but the hero you help gets a +2 on their roll. Failing a roll inflicts 2 stress on the hero who's trying, and 1 on any helper. A hero can only have one helper at a time. What does stress do? Currently nothing, but the "Rest" action reduces it.

In the baking scenario, you have 3 turns to win. In the battle scene, you have unlimited turns, but these "challenge steps" hurt you between turns! Lose all your health and you're knocked out. (Known bug: hero 0 can act even if knocked out. Easily fixed later.)

What I could do with this idea:
-Better designed, better looking UI of course.
-A sequence of adventure events. Find the cave in the forest while being chased by goblins, then explore the cave without getting hurt, then battle a monster. Conserve your resources to get through the whole sequence. Having lots of challenges plus randomness within a theme (no baking contests in the dungeon... probably) creates unpredictable adventures with some internal logic and room for expansion.
-Each hero has a mood with one of four good settings or one of four bad settings. Taking stress can cause heroes to "flip" to the bad setting, imposing penalties, while the good sides give various bonuses. Allies can help change a hero's mood. A "Brave" mood should help battle, while a "Calm" mood should help with logic.
-The narrator notes when it was a helper's +2 that saved the day. When this happens, let that event improve a relationship stat that boosts future teamwork bonuses and affects the story.
-Items.
-Some means of using the "wrong" skill on a challenge, creating hidden solutions. (I've got code for noting that such a solution exists, but not for using it.) An example is using an Animals skill to overcome what's normally a Fight roll. Using an inapplicable skill wastes your turn, so a little player thought is required. Ideally there should be an alternate ending to a challenge if you solve it a different way.
-A town between adventures, where you can buy stuff, train, and rest. You get to choose what sort of mission to go on next, giving you some control over the types of challenges you'll face. It should also be possible to swap party members.

Why ponies in this demo? I happened to be thinking first in terms of "Buck: Legacy", which is pony-themed. The "Fate" influence was about having allies create advantages for each other, which is tough to express in terms of a PC game. I ended up making this simplified helping system, which ties in well with the teamwork/friendship theme.

The intent is to use this battle system as the system for that wizard game, but it could work on its own, too, as something I could build as a complete game relatively easily. With the above features and a few dozen challenges it should be a respectable game.