Chess-like computer online game

I think you'll have to make a blind stab at initial values and then just go from there as you test it out.

For the base units vs the tougher units, you can think along the lines of, "On average, how many Peons should a Cavalier be able to fight before he dies?" and things like that, for adjusting hit points and combat stats. Base everything on comparison to your pawn. Then you can tweak against each other later; that's also where some special abilities can start being added to differentiate your bigger pieces from each other without just changing their combat stats.

Sounds like a pretty basic idea and you don't have a critical hook. Remember, the concept of "checkmate" is very dynamic in chess - I think that without using it, or something in a similar vein, you're really not making a chess game and instead making a turn-based tactics game (which is clearly what's going on).

It sounds like you should play some Final Fantasy Tactics or Tactics Ogre more and come up with a concept that really turns those games on their head (remember the "kill the leader" goals?). Failing that, find some chess variants to play (www.chessvariants.org) and see what comes of that.

http://www.chessvariants.org/d.betza/chessvar/buypoint.html

http://www.chessvariants.org/newideas.dir/construction.html

http://www.chessvariants.org/d.betza/chessvar/wand.html

http://www.chessvariants.org/crossover.dir/wotn.html

I wrote a computer game ten years ago that does exactly what you discuss. Not sure the reason for your post, but if you are interested in financing such a thing I still have the game engine sitting there idle.

As to programming the AI for this -- yes you are going to find a simple tree search algo not sufficient. It is easy to write AI that jumps a dozen moves ahead, albeit memory consuming. The problem is putting the thinking in the software to reflect all of the capable moves, and still give the human opponent a decent game.

The Chess variants page will have a lot of useful information for you.

For 100 units, I think you have to think about formulas to convert a tested set of characters (from another game) to your own stats and rules. Then you go through categories and levels to group them together and have a reference. Try listing them by race or alignment from lowest to top. i.e. 8 Unit Undead Army would be like skeleton-zombie-ghost-werewolf-mummy-vampire-lich-demon. Then do the balancing by layer.

Remember that chess balances armies, but every piece is worth different. Center pawns are not worth the same as lateral ones, and your bishop in the same color square that the enemy king, is worth more than the other one. Unbalancing pieces on the same army aids with group strategy. No game of chess is won by a single piece (you cannot check-mate a single king with just a queen in the board).

But as some have said, and I agree, you need a serious twist to make your game original.

Might I suggest that you only command a single character of the army? You could be fighting or have the player character off the board casting spells into the board. That would be hard on the AI program, but you could reward the character for his deeds, providing him the level-up hook that is so basic to the RPG dynamic. You could start as a simple shield-bearer and finish off as a Royal Paladin, or start as a stinking skeleton and become the fierest demon above hell.

Keep thinking!