Games like Rock Paper Frigate

84%Game Brain Score

Most mentioned positive aspects:story, gameplay

Most mentioned negative aspects:grinding, stability

84% User Score Based on 102 reviews

Space Battlecruiser is an arcade style, top down space shooter where you control a heavily armed capital ship. Battle against squadrons of fighters, fleets of warships, heavily defended space stations, and powerful command ships. Learn to master weaponry and special abilities like the Energy Shield. Upgrade your ship with salvaged material from your victories. If you enjoyed this game, see our list of games similar to Space Battlecruiser.

68%Game Brain Score

Most mentioned positive aspects:story, gameplay

Most mentioned negative aspects:grinding, stability

68% User Score Based on 266 reviews

The Pegasus Expedition is a story-driven sci-fi grand strategy game set in a key moment for humankind’s survival. Facing an overwhelming threat at home, humanity sends expeditions to the Pegasus Galaxy in a desperate attempt to find a refuge for the population of Earth. If you enjoyed this game, see our list of games similar to The Pegasus Expedition.

84%Game Brain Score

Most mentioned positive aspects:gameplay, music

Most mentioned negative aspects:graphics, grinding

84% User Score Based on 1,214 reviews

Critic Score 85%Based on 2 reviews

"You are outgunned. You are massively outnumbered. You must win." These are your orders. Humanity has already fought its war against the machines -- and lost. AI death squads stand watch over every planet and every wormhole, the few remaining human settlements are held captive in orbiting bubbles, and the AIs have turned their attention outward, away from the galaxy, to alien threats or opportuni… If you enjoyed this game, see our list of games similar to AI War: Fleet Command.

74%Game Brain Score

Most mentioned positive aspects:graphics, gameplay

Most mentioned negative aspects:story, stability

77% User Score Based on 900 reviews

Critic Score 66%Based on 3 reviews

Who needs backstory? Who needs resource-gathering? Diplomacy is so last year. Gratuitous Space Battles cuts right to the chase of sci-fi strategy games, and deals with large, completely unjustified space battles between huge opposing space fleets. If you enjoyed this game, see our list of games similar to Gratuitous Space Battles.

74%Game Brain Score

Most mentioned positive aspects:story, graphics

Most mentioned negative aspects:grinding, stability

74% User Score Based on 420 reviews

Engage in epic RTS warfare across three huge campaigns as well as other battle modes. Create your own fleet of ships, pick your side and enter into World War II naval combat on a global scale. Engage in epic real time strategy warfare across the Atlantic, Pacific and Mediterranean. This is naval warfare on a global scale. It is World War II and the age of the dreadnoughts has passed and naval war… If you enjoyed this game, see our list of games similar to Victory At Sea.

90%Game Brain Score

Most mentioned positive aspects:gameplay, graphics

Most mentioned negative aspects:grinding, stability

90% User Score Based on 1,786 reviews

AI War II is a grand strategy/RTS hybrid against an overwhelming, inhuman enemy who has conquered the galaxy. The enemy has made only a single error: underestimating you. You must steal as much technology as you can, and take enough territory to fortify your bases and launch your attacks. If you enjoyed this game, see our list of games similar to AI War 2.

55%Game Brain Score

Most mentioned positive aspects:gameplay, story

Most mentioned negative aspects:replayability, stability

53% User Score Based on 1,753 reviews

Critic Score 56%Based on 16 reviews

Sid Meier’s Starships challenges players to build a planetary federation by exploring the galaxy, expanding its influence and domain, researching futuristic technologies and engaging in deep, turn-based tactical space combat with an armada of uniquely customizable starships. Each new campaign will feature its own distinctive galactic strategy map of worlds with dynamically generated tactical comba… If you enjoyed this game, see our list of games similar to Sid Meier's Starships.

81%Game Brain Score

Most mentioned positive aspects:story, gameplay

Most mentioned negative aspects:grinding, stability

85% User Score Based on 2,930 reviews

Critic Score 76%Based on 9 reviews

Battlestar Galactica Deadlock takes you into the heart of the First Cylon War, to fight epic 3D battles that will test your tactical prowess. Take control of the Colonial Fleet from the bridge of the mobile shipyard, Daidalos, and free the Twelve Colonies from the Cylon threat. Build your fleets, protect the Quorum alliance and prepare to dig deeper into the conspiracies of this heroic conflict. If you enjoyed this game, see our list of games similar to Battlestar Galactica Deadlock.

68%Game Brain Score

Most mentioned positive aspects:gameplay, story

Most mentioned negative aspects:replayability, grinding

63% User Score Based on 248 reviews

Critic Score 88%Based on 2 reviews

A strategic-to-the-bone, star fleet command game in which deception, smart movement, and choices to battle decide victory or defeat. If you enjoyed this game, see our list of games similar to SPACECOM.

89%Game Brain Score

Most mentioned positive aspects:gameplay, graphics

Most mentioned negative aspects:story, stability

89% User Score Based on 610 reviews

Sword of the Stars: Complete Collection is the original Sword of the Stars games and the three expansions Born of Blood, A Murder of Crows and Argos Naval Yard. It is the year 2405, and human scientists have discovered a new technology that allows travel from star to star at speeds faster than light. But tragedy strikes, as Earth is ravaged by an alien force. The dawning of a new era was stymied b… If you enjoyed this game, see our list of games similar to Sword of the Stars Complete Collection.

64%Game Brain Score

Most mentioned positive aspects:gameplay, graphics

Most mentioned negative aspects:story, grinding

58% User Score Based on 207 reviews

Critic Score 84%Based on 2 reviews

Beyond the Sea is the comprehensive expansion for the acclaimed Renaissance economic simulator Rise of Venice. Beyond the Sea provides players with a whole new challenge by expanding the game world with 13 all new cities to explore and trade with, as well as all new residence missions and challenging new Doge tasks which will see your family playing a more important role. Beyond the Sea also allow… If you enjoyed this game, see our list of games similar to Rise of Venice.

45%Game Brain Score

Most mentioned positive aspects:gameplay, story

Most mentioned negative aspects:stability, grinding

38% User Score Based on 554 reviews

Critic Score 60%Based on 4 reviews

Etherium is the new, futuristic real-time strategy game developed by Tindalos Interactive, the studio that created Stellar Impact. This strategy game, exclusively for PC, offers a particularly dynamic and edgy gameplay with innovative game mechanics that revitalize the genre.In Etherium, three empires are engaged in a merciless struggle to control a handful of planets that contain rich deposits of… If you enjoyed this game, see our list of games similar to Etherium.

75%Game Brain Score

Most mentioned positive aspects:story, gameplay

Most mentioned negative aspects:replayability, optimization

75% User Score Based on 136 reviews

It's the 24th century and the colonization of space is not going well. Hyperspace opened the door to the stars, but habitable worlds are few and far in between, overpopulation is still rampant, and our civilization's appetite for resources has only increased. For over a hundred years, the incredibly rich Dust Zone sated this endless appetite, jointly controlled by the United Earth Nations and the … If you enjoyed this game, see our list of games similar to Dust Fleet.

70%Game Brain Score

Most mentioned positive aspects:story, graphics

Most mentioned negative aspects:grinding, stability

77% User Score Based on 1,242 reviews

Critic Score 58%Based on 5 reviews

Strike Suit Zero is an action-packed arcade space shooter set in the final hours of a future Earth. The clock is ticking; your planet is about to be destroyed and its only hope is the Strike Suit -- an advanced, transforming spacecraft that empowers you with ludicrous firepower and awesome abilities. Every second is precious; you'll be forced to fight with fury, choose targets on instinct and make… If you enjoyed this game, see our list of games similar to Strike Suit Zero.

80%Game Brain Score

Most mentioned positive aspects:story, gameplay

Most mentioned negative aspects:stability, replayability

78% User Score Based on 108 reviews

Critic Score 90%Based on 1 reviews

Take command of Naval Strike Group 7 and lead your fleet to victory in full 3D tactical space combat. Star Hammer: The Vanguard Prophecy is a sci-fi strategy saga that will test your skills as both capital assault ship Captain and naval fleet Commander. If you enjoyed this game, see our list of games similar to Star Hammer: The Vanguard Prophecy.

78%Game Brain Score

Most mentioned positive aspects:gameplay, story

Most mentioned negative aspects:grinding, stability

78% User Score Based on 4,016 reviews

In SPAZ 2 you must survive in an evolving post apocalyptic Galaxy. The zombie threat is defeated, infrastructure has collapsed, fuel is scarce, and scavenging means survival. Initially the Galaxy contains hundreds of fleets, each trying to survive. AI captains do everything the player can. If you enjoyed this game, see our list of games similar to Space Pirates And Zombies 2.

77%Game Brain Score

Most mentioned positive aspects:story, gameplay

Most mentioned negative aspects:grinding, stability

81% User Score Based on 1,950 reviews

Critic Score 67%Based on 1 reviews

Captain's Log, Star Date 2152. This is Space Crew. Its continuing mission: To defend Earth and humankind, to eliminate the extraterrestrial threat and to boldly go where no Crew has gone before in this unique, strategic, space simulation! If you enjoyed this game, see our list of games similar to Space Crew.

73%Game Brain Score

Most mentioned positive aspects:gameplay, story

Most mentioned negative aspects:grinding, stability

77% User Score Based on 3,978 reviews

Critic Score 68%Based on 19 reviews

Ancestors Legacy is a history-inspired, real-time strategy game influenced by historical events in the Middle Ages. The game combines resource management and base building with large-scale, squad-based battles across vast battlefields, all rendered in superb detail with Unreal Engine 4. Experience medieval bloodshed like never before thanks to the cinematic action camera that puts you right in the… If you enjoyed this game, see our list of games similar to Ancestors Legacy.

76%Game Brain Score

Most mentioned positive aspects:graphics, gameplay

Most mentioned negative aspects:grinding, monetization

76% User Score Based on 462 reviews

Welcome Admiral! Select your fleet, assign weapons, and sink the enemy fleet by controlling each of your ships down to setting the aim and range of each weapon's shot. Features include full open world Pacific & Atlantic campaigns, cross-platform multiplayer and awesome turn-based naval battles. If you enjoyed this game, see our list of games similar to Battle Fleet 2.

77%Game Brain Score

Most mentioned positive aspects:gameplay, graphics

Most mentioned negative aspects:stability, grinding

79% User Score Based on 5,870 reviews

Critic Score 70%Based on 2 reviews

Endless Space - Definitive Edition includes all the expansions and updates released for the game (including Endless Space Disharmony). If you enjoyed this game, see our list of games similar to Endless Space.

88%Game Brain Score

Most mentioned positive aspects:story, gameplay

Most mentioned negative aspects:stability, optimization

88% User Score Based on 1,297 reviews

To stand alone in war is extremely unpleasant. Extremely pleasant, on the other hand, is the stand-alone version Cossacks: Back to War. Containing all of the gameplay features of Cossacks: European Wars and Cossacks: The Art of War, this is a complete care package for all current and future Cossacks fans. This add-on contains 100 captivating missions taking place between the 16th and 18th centurie… If you enjoyed this game, see our list of games similar to Cossacks: Back to War.

89%Game Brain Score

Most mentioned positive aspects:gameplay, graphics

Most mentioned negative aspects:story, grinding

89% User Score Based on 2,383 reviews

Circle Empires is a fresh take on the RTS genre, featuring a fast-paced approach to conquering the world. The Circle Empires universe is made of interconnected circles, each containing loot to plunder and foes to defeat. You are the god-like leader of your tiny kingdom, hungry for power. Use your skills to hunt down increasingly powerful enemies and expand your empire. The game world changes ever… If you enjoyed this game, see our list of games similar to Circle Empires.

96%Game Brain Score

Most mentioned positive aspects:graphics, gameplay

Most mentioned negative aspects:story, stability

96% User Score Based on 2,100 reviews

Master of Orion 2 also known as MOO2 is considered the classic 4x turn based strategy game set in space. The game has a kind of cult status and even by to days standards is still only matched in game play by very few of its competitors. If you enjoyed this game, see our list of games similar to Master of Orion 2.

66%Game Brain Score

Most mentioned positive aspects:graphics, optimization

Most mentioned negative aspects:gameplay, story

73% User Score Based on 44 reviews

Critic Score 70%Based on 2 reviews

Non-stop galactic action awaits you in this arcade style tower defense game. Manage the defenses of the TSF Freedom Strike – humanity’s last hope against the hordes of invading alien spaceships. If you enjoyed this game, see our list of games similar to Infinium Strike.

90%Game Brain Score

Most mentioned positive aspects:story, gameplay

Most mentioned negative aspects:grinding, stability

90% User Score Based on 2,011 reviews

Experience the intense atmosphere of adventuring deep into the space. If you enjoyed this game, see our list of games similar to Battlevoid: Harbinger.

80%Game Brain Score

Most mentioned positive aspects:gameplay, graphics

Most mentioned negative aspects:grinding, stability

78% User Score Based on 1,273 reviews

Critic Score 90%Based on 1 reviews

Galactic Civilizations II: Endless Universe is a compilation featuring the content of Dread Lords, Dark Avatar and Twilight of the Arnor. It was released exclusively in Europe on September 26, 2008 and it was published by Kalypso Media. The compilation was released as Galactic Civilizations II: Ultimate Edition in North America on February 9, 2009. If you enjoyed this game, see our list of games similar to Galactic Civilizations II: Endless Universe.

63%Game Brain Score

Most mentioned positive aspects:gameplay, graphics

Most mentioned negative aspects:story, grinding

58% User Score Based on 1,064 reviews

Critic Score 67%Based on 16 reviews

Set sail and join the colonial powers of Spain, England, France and the Netherlands in their fight for supremacy of the Caribbean in the 17th century. If you enjoyed this game, see our list of games similar to Port Royale 4.

70%Game Brain Score

Most mentioned positive aspects:gameplay, graphics

Most mentioned negative aspects:grinding, optimization

72% User Score Based on 724 reviews

Critic Score 65%Based on 2 reviews

Port Royale 3: Pirates & Merchants is the third installment to the business simulation game Port Royale: Gold, Power and Pirates and Port Royale 2. It is set in the Caribbean during the 16th and 17th centuries. Created by Kalypso Media which founded Gaming Minds Studios in 2009 after Ascaron Entertainment went bankrupt, it combines a business simulator with real-time battles and towns that can be … If you enjoyed this game, see our list of games similar to Port Royale 3.

95%Game Brain Score

Most mentioned positive aspects:gameplay, music

Most mentioned negative aspects:story, grinding

95% User Score Based on 11,528 reviews

Cosmoteer (previously known as Starwright) is a 2D top-down starship design and combat game developed by Walt Destler for PC. The player's goal is to create powerful ships to destroy enemies for bounties used to further improve his fleet. If you enjoyed this game, see our list of games similar to Cosmoteer.

83%Game Brain Score

Most mentioned positive aspects:story, graphics

Most mentioned negative aspects:stability, grinding

93% User Score Based on 1,918 reviews

Critic Score 73%Based on 9 reviews

X-Morph: Defense Complete Edition includes: X-Morph: Defense core game, European Assault DLC, Survival Of The Fittest DLC, Last Bastion DLC If you enjoyed this game, see our list of games similar to X-Morph: Defense.

80%Game Brain Score

Most mentioned positive aspects:gameplay, graphics

Most mentioned negative aspects:story, grinding

79% User Score Based on 276 reviews

Critic Score 83%Based on 2 reviews

Beyond Sol is a unique blend of action combat and grand strategy empire building in a dynamic open world. Collect resources, build your city, upgrade your ships, and cultivate relationships or wage wars with rival cities in your quest to dominate the solar system. Play singleplayer or multiplayer. If you enjoyed this game, see our list of games similar to Beyond Sol.

87%Game Brain Score

Most mentioned positive aspects:graphics, gameplay

Most mentioned negative aspects:music, stability

87% User Score Based on 232 reviews

The award-winning Space Empires IV Deluxe is the latest edition in the Space Empires series. A grand strategy title in the space 4X (explore, expand, exploit, and exterminate) genre, Space Empires has already found a place in the heart of strategy gamers everywhere. Research technology, design new ships, wage war on a tactical level, put down rebellions, meet and greet new species, and much more.… If you enjoyed this game, see our list of games similar to Space Empires IV Deluxe.

80%Game Brain Score

Most mentioned positive aspects:gameplay, graphics

Most mentioned negative aspects:story, stability

80% User Score Based on 2,099 reviews

Ultimate General: Gettysburg is a critically acclaimed tactical battle simulator that allows you to lead thousands of soldiers in the battle of Gettysburg as commander of either the Union or Confederate army. The game features the most accurately created map, complex morale, innovative control mechanics and smart AI. You have the freedom to use different strategies while the battle progresses. … If you enjoyed this game, see our list of games similar to Ultimate General: Gettysburg.

75%Game Brain Score

Most mentioned positive aspects:graphics, gameplay

Most mentioned negative aspects:stability, grinding

75% User Score Based on 552 reviews

Write your own story and change the course of history as you lead of one of the Great Powers during the era of the First World War. Can you prevail as modern industrialized warfare changes the age of empires forever? Your actions will influence world events as you navigate a path through shifting alliances, emerging technologies and self-serving nations who hold power over vast populations eager … If you enjoyed this game, see our list of games similar to Making History: The Great War.

89%Game Brain Score

Most mentioned positive aspects:graphics, gameplay

Most mentioned negative aspects:stability, music

89% User Score Based on 1,560 reviews

Subvert the Empire. Crush the Alliance. Your Choice. Your Destiny. It is a time of great upheaval. The first Death Star has been destroyed, marking a major victory for the Rebellion. But the Empire remains strong. As commander, you must choose to take control of either the Rebel Alliance or the Galactic Empire. Your goal: complete domination of the galaxy. Take the galaxy by force. Take the gala… If you enjoyed this game, see our list of games similar to STAR WARS™ Rebellion.

68%Game Brain Score

Most mentioned positive aspects:story, humor

Most mentioned negative aspects:gameplay, graphics

68% User Score Based on 302 reviews

Salvation Prophecy is a military space epic. Human, mutant, and robotic factions are at war for galactic domination. Battles rage as space fleets collide. Invaders clash against fortified enemy colonies. Yet the greatest danger is the impending annihilation foretold by an apocalyptic prophecy. You must seek out the mysteries of distant alien worlds, and master ancient powers to withstand the comin… If you enjoyed this game, see our list of games similar to Salvation Prophecy.

81%Game Brain Score

Most mentioned positive aspects:gameplay, graphics

Most mentioned negative aspects:story, grinding

81% User Score Based on 291 reviews

Final Theory is a turn-based strategy game where you command fleets of battleships engaged in a galactic civil war. It presents an exciting experience for both veteran players and those new to the genre. It features innovative combat mechanics but also hearkens back to some of the classics of gaming. If you enjoyed this game, see our list of games similar to Final Theory.

83%Game Brain Score

Most mentioned positive aspects:story, gameplay

Most mentioned negative aspects:stability, grinding

86% User Score Based on 511 reviews

Critic Score 73%Based on 3 reviews

At the dawn of the 22nd century, the conquest of space and the colonization of the solar system is being monopolized by several huge and ambitious mega-corporations. Although extremely delicate and vulnerable, a balance is maintained by these companies. At the very edge of the solar system the companies make a discovery which will shift the technological advantage and upset the balance. And so a n… If you enjoyed this game, see our list of games similar to Nexus: The Jupiter Incident.

79%Game Brain Score

Most mentioned positive aspects:story, gameplay

Most mentioned negative aspects:optimization, replayability

79% User Score Based on 9,874 reviews

Critic Score 79%Based on 24 reviews

A ground-based RTS prequel to the classic Homeworld games. Assemble your fleet and lead them to victory on the shifting sands of Kharak in this compelling strategy game. Crafted by Blackbird Interactive, a studio founded by veterans of Homeworld and Company of Heroes, Homeworld: Deserts of Kharak takes players to the deserts of Kharak where danger lurks over every dune. If you enjoyed this game, see our list of games similar to Homeworld: Deserts of Kharak.

75%Game Brain Score

Most mentioned positive aspects:gameplay, graphics

Most mentioned negative aspects:story, replayability

75% User Score Based on 268 reviews

Aeon Command is a tug of war strategy game, where you play as one of three unique factions to help gain dominance over the Aeon Nebula! Take control of your mother ship to gather resources, produce ships and fight off the enemy mother ship. Grow stronger as you progress through the 24 mission campaign and unlock new upgrades. If you enjoyed this game, see our list of games similar to Aeon Command.

80%Game Brain Score

Most mentioned positive aspects:gameplay, graphics

Most mentioned negative aspects:replayability, stability

80% User Score Based on 337 reviews

ake Command and Secure Victory in the Great War! Commander – The Great War features a Grand Campaign covering the whole war from the invasion of Belgium on August 5, 1914 to the Armistice on the 11th of November 1918 in addition to 16 different unit types including Infantry, Cavalry, Armoured Cars. If you enjoyed this game, see our list of games similar to Commander: The Great War.

57%Game Brain Score

Most mentioned positive aspects:gameplay, graphics

Most mentioned negative aspects:replayability, grinding

57% User Score Based on 155 reviews

Once combat is initiated the player can lead their squadrons to attack waves of German bombers utilizing simple touch or mouse commands. The game follows the historical timeline very closely, but at the same time - the game mechanics are easy to learn (yet hard to master) and it provides great entertainment for both seasoned and novice players. If you enjoyed this game, see our list of games similar to The Few.

71%Game Brain Score

Most mentioned positive aspects:gameplay, graphics

Most mentioned negative aspects:story, grinding

71% User Score Based on 133 reviews

A space trader & combat sim meets squad-RPG, large scale conquest, choice driven gameplay with fluid & punchy tactical real-time combat set in a dynamic open-world sandbox. If you enjoyed this game, see our list of games similar to Star Nomad 2.

82%Game Brain Score

Most mentioned positive aspects:story, gameplay

Most mentioned negative aspects:grinding, stability

85% User Score Based on 3,520 reviews

Critic Score 78%Based on 6 reviews

Space tactical rogue-lite inspired by Dune and Foundation If you enjoyed this game, see our list of games similar to Crying Suns.

67%Game Brain Score

Most mentioned positive aspects:gameplay, story

Most mentioned negative aspects:graphics, grinding

64% User Score Based on 433 reviews

Critic Score 75%Based on 3 reviews

Can anyone build an empire in a place like this? Other factions are naturally suspicious of newcomers and may wage war at the first sign of unidentified craft. Here, a natural death is an uncommon luxury. If you enjoyed this game, see our list of games similar to Polaris Sector.

82%Game Brain Score

Most mentioned positive aspects:graphics, story

Most mentioned negative aspects:monetization, grinding

82% User Score Based on 1,596 reviews

Command a pirate fleet to sink ships, attack towns and smuggle wares. If you enjoyed this game, see our list of games similar to The Pirate: Caribbean Hunt.

83%Game Brain Score

Most mentioned positive aspects:gameplay, graphics

Most mentioned negative aspects:stability, grinding

87% User Score Based on 1,537 reviews

Critic Score 73%Based on 3 reviews

Research and master dozens of spells, conjure powerful enchantments and discover awesome spell combinations. Command an expansive range of units, all with unique abilities. Engage in epic battles with large armies marching across the landscape. Command the game Fight on the side of one of the eight gods. If you enjoyed this game, see our list of games similar to Warlock: Master of the Arcane.

61%Game Brain Score

Most mentioned positive aspects:gameplay, graphics

Most mentioned negative aspects:stability, grinding

55% User Score Based on 2,790 reviews

Critic Score 69%Based on 6 reviews

StarDrive 2 is an exciting and evolutionary step forward for the StarDrive franchise. In this eagerly anticipated sequel, the core mechanics have evolved to incorporate a turn-based strategic layer, featuring spectacular realtime battles. As the galactic ruler of your race you will lead your people into a procedurally-generated galaxy, exploring and expanding your space empire to greatness. Exploi… If you enjoyed this game, see our list of games similar to StarDrive 2.

90%Game Brain Score

Most mentioned positive aspects:gameplay, graphics

Most mentioned negative aspects:story, grinding

93% User Score Based on 2,148 reviews

Critic Score 70%Based on 1 reviews

NOVEMBER 5TH, 1983. Here, now, at the height of the Cold War, hundreds of America’s brightest men and women are poised deep underground in concrete bunkers known as Launch Control Centers, ready and awaiting the order to unleash nuclear armaggedon. Today, USAF First Lieutenant Derek Evans joins their ranks. And his first day on the job could be a big one. If you enjoyed this game, see our list of games similar to ICBM.

77%Game Brain Score

Most mentioned positive aspects:story, gameplay

Most mentioned negative aspects:stability, grinding

77% User Score Based on 1,318 reviews

Ultimate Admiral: Age of Sail is a tactical war-game from the creators of the Ultimate General series set amidst the epic naval campaigns in period of the American Revolutionary and Napoleonic Wars. If you enjoyed this game, see our list of games similar to Ultimate Admiral: Age of Sail.