Some Policies are Great, while others are absolutely Terrible. This guide covers the good, the bad and the ugly when it comes to Skylines Policies. Useful Policies These policies are ones which always or at least usually provide a significant benefit. The four must-run policies Parks and Recreation: Provides a land value boost which is always useful. Furthermore this policy acts by increasing the upkeep cost of parks and plazas by +25%, if you mainly use cheap parks such as small playground and small park (which you should, because all parks and plazas provide approximately equal benefit regardless of upkeep cost) then your parks and recreation cost will be very low, and +25% of practically nothing is still practically nothing. This policy increases the upkeep cost of Eden Project by 25%, but you probably wont need it once you have Eden Project. Education Boost: Unlike Parks and Recreation, this is a moderately expensive policy to run. However education forms the cornerstone of a wealthy and prosperous city, as such it is a very worthy investment. While it's a little hard to measure because the benefits take years to kick in, my cities which run Education Boost always seem to be a lot more profitable. The way education boost works, you only gain a benefit if there is free capacity in your educational facilities - there is no point in encouraging (and paying for!) more cims to be educated if there is no room for them. You can run Education Boost all the time, but it is most useful as soon as the University becomes available to quickly create a highly educated workforce. Small Business Enthusiast and Big Business Benefactor: These are absolutely the most potent and useful policies in the game. Commercial tax is based on sales, and so these two policies basically double commercial tax take. They are incredible and you should run them as soon as they become available. They are both fairly expensive, but the increased tax income more than makes up for it. Beware, doubling sales doubles the required goods deliveries, which will put a strain on your industry and your road networks. So these policies aren't quite a free lunch but the great gobs of tax income they generate more than offset the downsides. But if your traffic problems are greater than your income problems, consider not running them. Situational Policies Industrial Space Planning: This is a rather expensive policy to run, 6c per building is pricier than almost any other policy. Unlike SBE and BBF which double commercial tax income, ISP has no effect whatsoever on industrial tax income. However, it can double goods production; If your commercial doesn't have enough goods to sell you are missing out on commercial tax income and one solution is to run ISP to enable your existing industry to produce more goods. It can be useful as either a city wide or district policy, as a district policy it lets you increase goods production fractionally, by covering only some of your industry. Note that ISP functions by doubling the frequency with which industrial buildings dispatch vans and halving the resources required to create a van load of goods (meaning under normal circumstances, doubled goods production and unchanged resource delivery requirements). However, an industrial building is limited to having 2 vans at once - if both vans are already dispatched, it cannot dispatch any more vans until one returns. This severely limits the utility of ISP if vans take a long time to perform a delivery. ISP is thus best used when industry and commercial are spaced close together - it will likely provide little benefit if your industry is far from the commerce, but may help reduce import traffic. Recycling: The Recycling policy reduces garbage production by 25% - so it actually has a very significant effect. The reduction in tax income seems to be about 5.5%. Early in the game, garbage production is high and tax income is low. With increasing education and building levels, garbage production is reduced and tax income greatly increased. As such it makes the most sense to run Recycling early in the game - especially before incinerators. It also makes a lot of sense to apply Recycling as a district policy over industry, as industry generates a lot of garbage and pays little tax. Otherwise, in a late-game city Recycling will cost about 2x as much as simply building more incinerators would (for example in one of my educated cities, I spend $7200 on incinerators - while recycling would cost $4200 - far more than the $1800 I would save with fewer incinerators). However this comes with the proviso that recycling will also effectively reduce garbage trucks by 25% which will slightly help with congestion and agent limits. High Tech Homes: Of all policies, this is perhaps the most challenging to use optimally. On the one hand it provides a very potent benefit, on the other hand it is very expensive and the benefit is wasted if the residential building can reach lvl5 without HTH. Unfortunately, HTH costs the same for low density residential as it does high density, while the benefit for low density is much less. There are two very good ways to make use of HTH. The first is what I call "pulsing". Every so often, turn HTH on for a few seconds. This will cause a lot of residential buildings to level up. Then turn it off again. Most the buildings will remain leveled up (I speculate this is because higher level buildings provide a land value boost), essentially this uses HTH to "bootstrap" residential buildings to the next level, and you don't have to pay the upkeep. It can also be very useful as a district policy. After "pulsing" HTH you can apply HTH at the district level to maintain land value where houses will otherwise de-level. It is also generally useful as a district policy around the edges of the city such as coastlines, where it's harder to get high land values. Around the edges of the city, service buildings are half wasted, because the coverage area is mostly over water / empty space. On the other hand, HTH simply costs a few dollars per building, in this case it isn't wasted. Finally if you don't tend to provide that many services, aren't into micromanaging districts, or are playing the hard mod (which makes it harder to achieve land value targets), you might benefit from running HTH all the time. It is good value for money when it enables most residential buildings to be a level higher. Normally the Eden Project will obsolete HTH. Policies which should not be used It can be summarized that anything which didn't appear under Useful Policies, is not useful. However there are a number of policies I would positively avoid, either because they are incredibly expensive to run, or tend to provide no actual benefit. Extremely Harmful Policies: Power Usage: This policy costs an absolutely horrendous amount to run and only reduces power use by a small amount (~11%), it's very difficult to imagine a scenario where that money wouldn't be better off spent on new power plants (or raising your electricity budget). Want some numbers? In my current city, I spend $3220 to generate 464MW, while Power Usage costs $14600 and reduces usage to 399MW. It would cost $600/week to generate that power with advanced wind turbines, at a saving of $14000/week. Water Usage: Just like Power Usage, this is a policy which is horrendously expensive to run (the numbers are the same as for Power Usage), you're far better off just upgrading your water capacity or adjusting the budget than flushing money down the toilet with Water Usage. Smoke Detector Distribution: Quite possibly the worst policy in the game - no exaggeration. It is very expensive to run (the numbers are the same as for Power Usage) - it could easily cost as much or more as complete fire coverage, and you would be much better off spending the money on building more Fire Stations. Fire Stations not only do a superb job of putting out fires, they also provide an incredibly useful service rating and land value boost - Fire Coverage is one of the most universally desirable and beneficial service types (being particularly loved by industry, but appreciated by all) and if you build enough fire stations to take advantage of the fire service rating you will have zero problems with buildings burning down. Frankly, you should prefer cutting off your own nose to running Smoke Detector Distribution. Non-useful Policies: Pet Ban: Pet ban reduces garbage production by a measly ~5%. Why don't you just enact Pet Ban while twirling your mustache then kick a puppy to establish that you are a bad guy? No idea how the economics works out since happiness is hard to quantify but clearly a policy for villains. Smoking Ban: There is absolutely no reason to run this policy because Cims wont have serious health problems unless you do stupid stuff like zoning residential in polluted places. Good city management - buffering residential from ground and noise pollution, and not forcing them to drink poo water, will result in an incredibly healthy population and empty hospitals. So unless you want to make your cims unhappy (and hey, I'm not judging you) don't run this policy. Free Public Transport: If you make a functional mass transit system (and you should, because transportation rating is the most important of them all), cims will be extremely happy to use it and pay for the privilege. Usually your greatest problem will be full vehicles and overcrowded bus stops; so why would you give up fare income to make your capacity problems worse? Schools Out: No, just god no. This is like the polar opposite of one of the most useful policies in the game: Education Boost. As such, it must logically be one of the least useful and most destructive policies in the game. It has minor flavor utility as a district policy making it possible to have low education districts - Schools Out is the only way to accomplish this as cims will travel any distance to get an education. Harsh Prison Sentences: While it's nice that the developers want to cater to tyrannical iron-fisted mayors, there is no good reason to run this policy. You need to build quite a few police stations for the service rating / land value boost and crime should be no issue at all. However if you have room in your prison cells it is basically free to run. Please note I am not bothering to mention those policies which are obviously shooting yourself in the foot, such as "High Rise Ban". Such policies exist for flavor reasons alone. Most of these policies (such as Schools Out) are fine to run for flavor purposes. Also feel free to run the expensive policies if you have more money than sense (hopefully due to having a great surplus of income rather than an absence of sense). Transport Policies There are a group of policies specially related to transport, namely: Heavy Traffic Ban. Old Town. For the most part there should be no reason to use such policies. Bypasses (highway ramp tunnels work well) should always exist to let truck traffic go around or under residential districts, and the trucks should prefer the bypasses because they are shorter/faster. Cargo Terminals located in industrial districts can also almost entirely eliminate truck traffic from city streets. One legitimate use of Heavy Traffic Ban is to force industry to use cargo terminals, while it will normally do so voluntarily, there might be some cases where trucks see a more direct route by road and HTB can be used to block of that route, freeing it up for non-truck traffic. There are also the two policies related to bicycles: Encourage Biking Bike Ban on Sidewalks There is no conceivable reason why you wouldn't want to run the former because it is free and reduces motor traffic, and on the other hand there is no conceivable reason why you would want to run the latter; bikes are unable to use roads and as such banning bikes from sidewalks is equivalent to banning bikes from all parts of the city which don't have bicycle lanes. Bikes on sidewalks don't seem to cause any harm so the only reason to run the policy is for flavor purposes. If there is one slightly insidious use for Bike Ban it is that it can force cims to use mass transit and thus pay fares, but presumably at the expense of also increasing car traffic. Taxation Policies Generally there is is little reason to visit the Taxation Policy tab. These policies are equivalent to setting the taxes under budget. The only time I ever used taxation policies, was when unlocking the building which requires running 4% taxes - you can use the tax raise policies to effectively run 6% taxes. The intent of the tax policies appears to be aimed at district policies - it permits raising or lowering taxes for particular districts by +/- 2%. Higher level buildings are more tolerant of high taxes, so if you're into micromanagement you can run about 11% taxes, then tax your lvl5 residential at 13%, while taxing your lvl1 residential at 9%. I do not recommend this; generally speaking the game is not financially challenging enough to bother with micromanaging taxes. But it does appear to the intent of these policies. Exploits, Tricks and Strange Stuff This section is about exploitable mechanisms or things which sound like exploits in theory but don't actually provide the anticipated benefit for reasons of underlying gameplay mechanisms, I don't really advocate integrating this knowledge into your game - it's better to play naturally. Nevertheless, it is included for completeness. Buildings which cost $X per building, really do cost $X per building, whether it's a 1x1 low density residential or an International Airport. The cost is not normalized. This can be readily exploited to increase the cost-effectiveness of Big Business Benefactor, Small Business Enthusiast, Industrial Space Planning and High Tech Housing - simply do not zone small lots, so that most lots will be 4x4 or 3x4. You can avoid paying the price for Recreational Use by using it as a district policy which excludes police stations (or by placing a district over police stations and turning off Recreational Use for that district). The Recycling policy incurs no cost when applied as a district policy over non tax paying buildings, and still reduces garbage accumulation. It's a free lunch! (though of garbage) You can use Smoke Detector Distribution as a district policy over power stations to reduce the chance of them catching fire and causing a blackout. However, there is no actual harm caused by temporary power outages, a building without power still pays full taxes, so while this sounds like a neat trick it will likely accomplish nothing since temporary power cuts cause no harm. By the same token, most other ill effects, such as being on fire, lacking water, garbage accumulation or crime, cause no actual harm as long as they are corrected before leading to the building being destroyed or abandoned, making preventative policies less useful than they could be (i.e. a preventative policy is not useful unless buildings are ACTUALLY being abandoned). You cannot use Water Usage or Power Usage selectively as a district policy to save money - consider the exception which proves the rule: The International Airport is by far the most power-hungry building in the game. It uses 4MW of power which costs between $40-64 depending how expensive your electricity is, Power Usage will reduce that by between $4.4 and $7 - however since it costs $5 you can only save $2 at best. And the International Airport uses about twice as much power as the next most expensive buildings. On the other hand, Water Usage can reduce the water/sewage cost of the incredibly thirsty Nuclear Power Plant by a mere $1.7, not even coming close to the $5 cost. So on sum, you can save $1-2 by applying power usage as a district policy over the International Airport, and only if you're exclusively using really expensive electricity such as Oil, and then after 10 years you can buy a small park from the savings.