In Ban the ban: essential game design advice (with examples), Nick Bentley talks about the cognitive dissonance of establishing rules and then creating special “but you can’t do X” rules to prevent problems.
Why do such rules exist? The most common reason is, during play-testing, the designer discovered players want to take an action that would hurt the experience – for example, a too-powerful action every player would take every turn if allowed. The most obvious fix is to ban it.
He then goes on to explain how doing the most obvious fix is a bad solution.
Banning otherwise-expected actions means the rules become harder to learn and the game play itself becomes awkward as you are constantly checking your planned actions against the rules.
Bentley’s post is a fascinating bit of insight into how a design problem can turn into a design success. By not banning actions, you have to allow for them. The entire point of banning a move is because it is unbalanced or otherwise ruins the game, so how do you allow it without the game suffering?
Interestingly enough, the answer can sometimes mean a much deeper and more compelling game.
Basically, take the action that you deem is too strong and assign a huge cost to it.
Bentley gives a couple of examples and a counter-example to see when it makes sense to include a ban, but the result is a choice that makes sense within the rules and can sometimes result in a more strategic game.
While Bentley is talking about boardgames, you can see how it would be applied to video games.
For example, if your game has inventory, you could limit the amount that could be carried. If a player with a full inventory comes across some new loot, the choice is to get rid of something to carry the new thing or not pick it up. Think Diablo or Minecraft.
NetHack, however, allows you to carry whatever you want, but it balances it with an encumbrance penalty. The penalties get more and more severe as you collect more things. You start off with penalties to speed and attack ability. If you carry too much, the penalties include not being able to walk up or down stairs, getting hungry faster. Carry even more, and you start taking damage for each move you take, and eventually you can get to the point where you can’t move at all.
Instead of arbitrarily deciding that a player can’t carry that much inventory, you turn it into a strategic choice. Do you want to struggle to carry all of the groceries from the car into your apartment so you can do it in one trip, or are you going to make multiple trips so it is easier?
You can see how this method of balance would apply in terms of limits on the number of units in a real-time strategy game. Some games add an upkeep cost which increases after you add so many units. Now I can choose to have too many units in my army temporarily if I’m willing to pay the cost, say for a large offensive push or to defend against the same.
“You can’t perform this quest. You don’t have a sufficient experience level.” No, by all means, try to perform the quest, but it is going to be incredibly punishing. The balance is already built in here!
Sometimes limits are technical in nature, such as the number of units you can have in your army at once. Still, you can see how allowing the player to decide if a decision is a poor one or a good one despite the cost means a deeper play experience than it would have been if you were limiting things arbitrarily.