FPGE and direct editing of content under PGF allow Modders to do many interesting things. However, when it comes to Players, content editing in no way circumscribes the limits of their gaming experience. There's another aspect to playing which enriches gameplay tremendously: "House Rules" (HRs).
HRs are akin to contracts that human players voluntarily enter into (many times just with themselves !) which invariably commit them to abstain from engaging in certain actions that are normally available during gameplay. The main idea here's that human players possess the discipline to police themselves (on the honor system) in adhering to such "contracts" even in the face of... extreme battlefield adversity !
For example, within the context of the rather well known Submarine Stubbornness "oddity", a PGF aficionado clearly possessing a sense of humor posted elsewhere on the Web:
As for multiplayer, there can be just a house rule "we do not set epic fortifications with submarines in ports".
Naturally, this kind of HR applies to human behavior. On the other hand, PGF's AI knows not of honor systems and the like; its sole ethical master is the... source code !
In the past, objections have been raised in regards to the obvious fact that PGF's AI cannot "take advantage" of HRs and consequently (?) it's "unfair" for human players to engage in such... unorthodox practices. My response has always been as follows:
a) Since when are humans obligated to "obey" machines ?
b) Asymmetrical gameplay capabilities aren't necessarily unfair. In chess, Rook vs. Bishop & Knight endings are definitely asymmetrical but hardly always unfair. Closer to PGF, is it not asymmetrical warfare when the AI is often given oodles of prestige that its human adversary can only dream of ?
PGF's underlying programming makes no serious allowances for "sophisticated" play by its AI Module... Now, it may not be totally unreasonable to consider such behavior to be akin to a bunch of AI Module de facto
HRs. To boot, adherence to such HRs is one-sided -- at least in principle. Of course, there's nothing that stops an "AI Warrior" from... returning the "favor", thus re-establishing... "fairness" through "symmetry" !
It's also somewhat interesting to consider the fact that it doesn't matter an iota whether the AI Module might not have been the beneficiary of top notch programmer involvement... In the present context, the only thing that's pertinent is the AI Module's actual play behavior and an "AI Warrior's" purposive response to it.
Gentlemen, you may try letting your imagination loose and see what happens when one cuts off the umbilical cord of "SSI-Style Campaign Orthodoxy"...