Balancing Costs & Cards

I missed your description in another post so initially asked for details on gameplay. Now that I've read that, I understand a bit better, but want some clarification.

So, what you have is a 2-player game wherein each player has a custom deck, and the basic gameplay consists of players in turn drawing from said deck, "calling" Creatures into play, and battling the opponent. "Variables" are cards that give rule-bending effects.

I'm not clear on what the "Main" portion of your turn scheme is for, as it appears the major phase is battling. I'm intrigued by the whole Positive/Negative thing (how about a name change: "Litmus Test of Wills!!") though I wonder how you'd represent the Balance change, component wise.

On your actual question, are you asking about Balance Values for Creatures, Variables, or both? If I've understood your rules summary, Creatures are your currency. To get a new Variable?/Creature? in play, you propose returning to your hand (shouldn't that be discarding?) any combination of Creatures from the table to cover the cost, each Creature having either a Positive or Negative value.

At first glance, I think you've got that backward. Creatures in play should make it possible or impossible to introduce Variables by virtue of how Positive or Negative your environment is. Maybe I'm hung up on the whole litmus test thing, but what I'm picturing are various monsters surrounded by a either a bright orange (Positive) or dark blue (Negative) aura. Orange limits blue and vice-versa, so the more Positive you are, the more Positive Variables you can bring into play. The more Negative you are, the more Negative Variables you can bring into play. It's like how certain organisms thrive at an acidic vs a basic pH. Perhaps it's always possible to bring in Variables of either kind, but they come in weaker in a hostile environment.

For example, say the player has one Creature at 3 Negative and one at 2 Positive in play. This would give a Balance of -1. If the player played a +3 Variable, that Variable's effect would be diluted by 1 point. What that dilution would be would depend on the card. To borrow your example:

Bounce (+3)
Discard Creatures equal to this card's power from your opponent's field.

In my example, the player using Bounce would be able to discard any +2 Creature from the opponent's field, or two +1 Creatures. Interestingly, if the player had a Balance of -5 when playing this Bounce, he could discard Creatures worth -2 instead. So the card is strongest when both players have a positive Balance, and useless at exactly -3.

Feel free to use or disregard this idea. Also please let me know if I've fundamentally misunderstood your rules.

This is a completely different game but still sounds pretty good. Though in this new scenario, if you just play positive creatures your "positive power" will keep on increasing and increasing, which might not be a bad thing, but there should be some way of encouraging a player to also play negative cards. A cute idea would be to expand this to multiple colours (say 5) where different colours subtract from two other colours, but if you play alot of a single colour you get a boost effect. This is a very cute way of creating Verstility vs Power.

Back on topic. I think applying values to card effects, going with basically gut-feeling, is a good idea. Then as you playtest you will get a better feel for what cards *should* cost. Why is this one so expensive? Why is this one so cheap? Then you can alter your values to bring them more in line with what they should be.