Protective is an exceptionally boring and weak trait. The huge flaw in the Protective trait is that if your opponent isn't attacking your cities, Protective effectively does nothing. When are any of the other traits ever not useful? Financial will always earn you extra commerce. Creative will always give extra culture. Organized will always save you money on civic upkeep.
"Well, if I'm never at war, then Aggressive isn't useful."
"Or if I never use specialists, then Philosophical isn't useful."
"If I never build wonders, then Industrial isn't useful."
This is the thing though. Even for those "situational" traits, you can always push their advantages. Aggressive isn't useful if you aren't at war, but you can actively pursue war. Philosophical isn't useful if you don't prioritize great people, but you can if you wanted to. I’ve never really thought of these traits as genuinely situational because I could always play to their advantages. I could even say the same for Imperialistic (a trait I thought would be super broken until I remembered that settler spam doesn’t work in CivIV), but the idea of playing to Protective’s advantages is mind boggling…
“I’m going to wait for my opponent to declare war on me and then sit around in my cities, waiting for him to attack me.”
If you can even call that playing to your advantages. Even supposing you instigated the war, you’d still have to hole up in your cities and wait for your enemy to attack to “benefit” from the trait. Whether or not the trait is useful depends almost entirely on what your opponent chooses to do. The hilarious irony of the Protective trait is that the situations in which it’s most useful are generally the ones that you want to avoid in the first place. Do you really want to fortify in your city while the enemy lays waste to your countryside? Do you really want a trait that shines out when your cities are at risk of being captured?
Now defense is a good thing; I wouldn’t train City Garrison II longbowmen if I didn’t believe that to be true. But actual city defenders are only half (if even that) of an effective defense. City defenders help ensure that only dedicated attacks will take your cities, but you’re in serious trouble if you can’t actually force the attackers off your territory. Walling up in your cities isn’t an ideal strategy, and it’s certainly not something I want to devote a trait to. This is also why Aggressive is just as useful, if not more so, on defense as Protective. Archers and longbowmen don’t have the base strength to fight effectively outside of cities, so melee units are essential even when defending. Aggressive’s free Combat I promotion is useful here, but it’s doubly useful when it provides easy access to promotions like Shock and Pinch. After gunpowder enters play, this disadvantage is somewhat lessened since gunpowder units are good attackers and defenders, but that’s far too long to wait for this glaring shortcoming to go away.
The funny thing is, even if I didn't use specialists or build wonders, I would at least get use out of the building production bonus (university and forge) for the Philosophical and Industrial traits. Protective gets a production bonus for walls and castles, which is bad for a trait because it again relies on a city being attacked to come into play. Aside from that, walls and castles are bad buildings for bonuses because you only want to build them in border cities. As a Creative leader, I could build libraries in most, maybe all, of my cities, if not for the research bonus, then for the culture and scientist slots. How many cities am I going to want to build walls in? Not many, maybe even none. Then to add insult to injury (or maybe the other way around, I forget), THEY GO OBSOLETE. I’m laughing as I’m typing this right now; it’s just reason on top of reason on top of reason why Protective’s fast walls/castles is such a miserable bonus.
So yes, Protective could definitely use a rehaul. Here are some suggestions to improve it (mix and match these as you choose, I don’t mean to say that Protective get all of these bonuses):
• Units receive a small strength bonus (10%-20%) when in combat inside your cultural borders, whether attacking or defending. Archery and gunpowder units get fewer and/or different promotions to balance this effect out (ex: free Combat I instead of City Garrison I or Drill I).
• You can draft a small number of units per turn.
• Units suffer less collateral damage (20%-33% less).
• In addition to +100% production for walls and castles, +100% production for bunkers and bomb shelters.
• +25% production for archery units (NOT gunpowder units).
