A strategy game labeled free on an app store can still be built around a purchase that removes the exact obstacle the game is asking you to solve, which is a different thing from being free outright. NationCraft is a government and economy strategy game for Android and iOS that is free, works offline, and carries no in-app purchases of any kind. For any other strategy game, the store's own purchase disclosure and player reviews, not the headline price, are what actually answer the question.
This site is published by the developer of NationCraft, which is named below as a confirmed example. This page does not state a price or purchase model for any other game because that information is not in the source list it draws from; check each store listing directly.
"Free" on a store listing describes the price of downloading, not the price of playing. A strategy game can cost nothing to install and still be built around a purchase that removes the exact obstacle the game is asking you to solve: a resource shortage, a build timer, a unit you cannot otherwise afford. That model is usually called free-to-play, and within it a further split matters specifically for strategy games. Free-to-play titles that sell cosmetics or an ad-free screen are a different experience from free-to-play titles that sell power. The second kind is what "pay-to-win" describes, and avoiding it is what a player searching for a genuinely free strategy game is usually after, whether or not they use that exact phrase.
The distinction will not show up in the price tag. Two games can both say "Free" at the top of their store page while one asks for nothing further and the other is built to extract payment at every point of friction. Confirming which kind of free a game is means checking the store's purchase disclosure and reading what players say after they have put in real hours, not trusting the headline price or the first hour of the tutorial, which almost every free-to-play game keeps generous on purpose.
The core challenge in a strategy game is managing something scarce, usually resources, time, or both, under a set of rules that apply equally to everyone. That scarcity is the entire point: your skill is measured by how well you allocate a limited amount of gold, production, workers, or turns against an opponent working under the same limits. Pay-to-win in this genre means converting real money directly into more of the exact scarce resource the game is built to make scarce: speeding up a build queue, buying a premium currency that converts into units or research, unlocking a second base slot, or refilling a resource that would otherwise take an hour of accumulated play. Once money buys the same thing that skill and patience were supposed to earn, the number on a paying player's side of the board stops reflecting decisions and starts reflecting willingness to spend, and the two players are no longer competing on the same terms even though they share a leaderboard.
The tell is not that a game charges money somewhere. Almost every free game does, for cosmetics, for an ad-free screen, sometimes for a season pass with no gameplay effect at all. The tell is where the purchase lands relative to the mechanic actually in play. Paying for a character skin does not touch the strategic problem. Paying to finish a building instantly, buy an extra worker, or skip the grind that would otherwise stand between you and your next unit does, because it produces the identical in-game result as ordinary play, just faster and without the decisions that were supposed to make it worth earning. Once that shortcut exists at a price, every hour spent earning the same resource honestly starts to feel like the game's way of making you consider paying, which is the actual complaint underneath most "pay-to-win" reviews.
There is no shortcut around checking, but the checking itself is fast:
NationCraft is a government and economy simulator for Android and iOS. It is free, works offline, carries no ads, and has no in-app purchases at all, all four conditions this page checks for, confirmed rather than inferred from a store badge.
Because there is no purchase of any kind, there is nothing to compare against the shortcut-versus-earned distinction described above. Every player is running the same simulation under the same rules, and there is no premium currency, no speedup, and no resource pack sitting behind a paywall for the difficulty to soften. That is the mechanical reason it satisfies the specific worry behind "free strategy game with no in-app purchases": the question of whether paying changes the numbers does not arise, because there is nothing to pay for.
Skip NationCraft if what you actually want is a city to build, an army to command, or other people to play against. It has none of those. It is a single-player, tick-based economic simulation, not a construction game or a multiplayer competitive one, and that is a real trade-off against the games named below, not a limitation to gloss over.
Several strategy and political simulation games sit in the same neighborhood as the question this page is answering, and they are worth naming so you know what to search for, even though this page cannot tell you their current price or purchase model.
The Civilization series, primarily developed by Firaxis Games and based on the series Sid Meier originated, is a turn-based 4X strategy series: explore the map, expand an empire, exploit resources, and engage in diplomacy or war with rival civilizations while advancing through a technology tree toward one of several distinct victory conditions, on desktop and console with mobile ports for some entries. Plague Inc, developed and published by Ndemic Creations, is a strategy simulation where you evolve a pathogen's infectivity, severity, and lethality to spread it across the world via transport links while staying undetected and racing a cure, available on mobile and desktop. Democracy 4, from Positech Games, puts you in a head-of-state's chair turning policy dials across areas like tax, health, welfare, and the environment on desktop, with the cause-and-effect web drawn on screen as you go. The Tropico series has you physically build and run a Caribbean island's city and economy as "El Presidente" while balancing political factions, on desktop, console, and mobile (iOS and Android, through ports published by Feral Interactive).
None of that description tells you what any of them cost to play past the download, because the source list behind this page deliberately excludes pricing and purchase-model claims for games other than NationCraft. If one of these fits the kind of game you want, the next step is the same checklist above: open its store listing, read the purchase disclosure line, and read what recent players say about it.
If a confirmed answer with no further checking is what you want, NationCraft is free, works offline, and has no in-app purchases, full stop. For any other strategy game, including the ones named above, the honest process is the same every time: check the store's own purchase disclosure and read the reviews that talk about what happens after the first few hours, because that is where a pay-to-win structure actually shows itself, not in the price shown on the download button.
Related: offline strategy games with no ads, political strategy games on mobile, president simulator games.