In one game I had buildings, then in next version of the game I made the power usage of buildings and introduced power plants. Substantial number of players said they disliked it, not hate or demanding "revert it back" and not majority but still a substantial number. It was not a dumb feature with linear buildings to power plant ratio, there were technologies that increased output of powerplants or reduced overall power usage or combined technologies that increased lasers strength along with power efficiency, experimental anti matter generators in special buildings... I'm pretty sure the feature enrichted the game as a whole and added some strategic decisions.

Probably connected thing, when I played Civilization 4 I wildly enjoyed the lack of upkeep for buildings compared to Civilization 3. It was surprising, why have I enjoyed it so much? I would certainly define myself as a heavy strategy lover, so why I enjoyed the dumbed down no upkeep model?

Is it a gamedesign flaw when buildings/other things require some upkeep/energy to maintain? Should we avoid it? Or maybe it is something else?

Upkeep is a fine feature. I've seen it used successfully in a number of games. The key is to keep your upkeep to income ratio low.

The reason players are complaining is because they like positive rewards. Building buildings in your game is obvious 'fun' for the player, and by adding a restriction like this, you are taking away 'fun' that they are use to receiving. This will cause a lot of grief to your current player base.

Another thing you have to keep in mind is that players have different personality types. In fact, there has been a suggestion that there are 4 primary gamer personalities. The Killer, the Explorer, the Achiever and the Socialite. Killers, Explorers and Socialites probably didn't mind the changes, but the Achievers, the ones who want to have millions of buildings and unlock all the games technologies, probably had the hardest time coping with the new restriction.

Just my 2 cents.

Upkeep is a solid mechanic when you want to encourage the player to get by with less of something over time.

I doubt upkeep served a very interesting function in Civ3.

What strategic decisions do your powerplants force the players to make?

Upkeep is a fine feature. I've seen it used successfully in a number of games. Like? As a player I only enjoyed progressive upkeep in Warcraft 3 since it "allowed" me to get rid of some units and make me not agonize over lost units so much "I lost them, fine, I will pay less now".

Upkeep is a solid mechanic when you want to encourage the player to get by with less of something over time.

Yes... But assuming we don't have to add upkeep for the sake of game balance. Should we still add it for the purpose of enriching the game?

What strategic decisions do your powerplants force the players to make?It was not about powerplants but about energy. You could get energy by building powerplants or by going technological route. And the technological route provided several options whose effectiveness was affected by your overall strategy and other elements you invested in. There was also a choice of one time constant energy boost or percentage energy boost (+50 to energy is good short term, but in a long term +5% gives more). Anyway, the question is not about the example given, I mean upkeep as a concept in any shape & form.

Upkeep was successful in (off the top of my head): Age of Wonders series, Total War series, and Lords of Magic. The way I see it, upkeep is a way to encourage players to build their economy in the early game rather than going all-out with a large army. The player with the smaller army will have a very quickly growing economy and can invest more, and this is compounded when there is a per-turn cost for having military units.

Making economic buildings have upkeep seems like an odd decision to me. I guess it encourages the opposite - build an early army because you can't sustain early economic growth.

Players probably disliked upkeep because it threw their old strategies off balance, not because of upkeep. Same thing happened in Civ V with happiness. I have a friend who did not like it because his tried and true strategy of amassing a big population every game did not work anymore.

Upkeep is a fine feature because it puts a generic negative aspect to improvements. Because it is generic, it can be easily compared. If improvements come with unique negative aspects, you need to compare 4 things, the 2 positive and 2 negative aspects. With a monetary upkeep, the improvements can be compared with their positive aspects only.

Upkeep also adds strategic depth to your game. The more you have, the higher your upkeep. This creates a risk/reward situation where you can either play it safe in the short term, but risk falling behind in the long term or be risky to minimize upkeep and be stronger in the end. You then have a RPS relation for early game where : army > economy > balance > army. You need these RPS relations to create strategic depth, else it becomes a matter of finding the optimal building configuration.

Upkeep was used successfully in Ogre Battle. In it, each unit had military strength, and upkeep cost. You had to balance strength vs. cost. It was a good mechanic.

So, 2 points:

1) Upkeep can provide a reasonable, easily understood mechanic for limiting the number of items you can possess.
2) By limiting quantities, you force more difficult choices. And the act of optimizing choices is fun.

Again, the key here is to not over-limit the player (give more, require less). In Sim City, a very classic game, one coal plant could sustain perhaps 40 buildings, whereas one nuclear plant could support 80 buildings. If your game requires one power plant per building, I can see why players would not like this. I'm taking a shot in the dark here, but I bet if you up the power output of a plant by a factor of 2, your players would love you for it.

No one said that upkeep is fun... Or that it enrich the game on its own. It seems that upkeep is an acceptable method to achieve some game balance goal (like limiting spending/army/growth/expansion), but has no place to exist on its own. In short, upkeep is slightly bad feature, but easily accepted by players.

An interesting "upkeep" was energy in Civilization. Your factories do not require energy, but these work better if you provide energy. It was a positive bonus that was not seen as an upkeep or as a cost, still from designer's perspective it worked very similar to upkeep since everyone was building factory with powerplant in the near future in mind... I wonder if such model is not better.