I've always loved WWI flying movies (The Dawn Patrol, The Blue Max, Flyboys). Over the years I've attempted to translate the excitement of these movies into a game format, utilizing various often complex rules systems to simulate combat, and tacking on RPG elements.
In Harms Way: Aces In Spades has an elegant and simple (well, as simple as anything that can be which recreates the feel of WWI aerial combat) combat system that will not dominate your gaming night with one or two dogfights and no real roleplay. The system produces the 'feel' of aerial combat in canvas and wood scouts through the use of 'Energy Units' that are gained by diving or burning fuel, and are lost by climbing and maneuvering. Many of the Great War's aircraft are numerically defined in the game, and the system is simple enough that any additional favorites can be added in moments. Shooting and damage are likewise simple (a D100 is all you will need), with a system to simulate luck and critical hits. This produces the flavor of the first dogfight in The Blue Max, for example, without bogging the player down in calculations and measurements.
The roleplay system is likewise elegant and stands somewhere between a diceless rpg system and a simple dice-based system. Characters are created by allocating points and skills are gained through comparison of social class and one's chosen background. Well-rounded characters can be rapidly created, and there is a system for quickly creating 'supporting cast' characters. Each player has a 'main' character, the pilot, another supporting officer (medical, administrative, observer, etc.), and an enlisted man who is a specialist at the aerodrome. If the 'main' is injured or captured, or unaccountably absent after visiting the local social establishment, the player can pick up one of his 'troupe' and game with him until his 'main' returns. This is a very clever concept and again recreates the 'movie' feel that the game works hard to develop.
As with all games that cover complicated historical events, the author of In Harms Way: Aces In Spades had to decide how much historical detail to include. The book is not a campaign resource for World War One. There are no maps, descriptions of historical pilots, or even historically accurate images of WWI aircraft. However, with so many resources available on the internet, the referee will be able to find all necessary background outside of this text. And it is important to remember that this set of rules attempts to recreate the feel of the idealized war in the air, not the actual war (although it could easily do that, too). Players compete for 'notice' to gain rank and medals, and all sorts of strange and audacious acts could qualify, or not, depending upon the personality of the Squadron Commander.
The book contains occasional typos. Also, some essential information can be difficult to find (ie., how to add up a player's hit points). A good 'referee's sheet' with essential data would go a long way to making what is about 140 pdf pages more accessible. However, these are minor complaints in what is a highly creative, fun, and easy to implement game system in an historical period that many of us have longed to recreate but just couldn't find that ideal balance between a technical air combat system and roleplay.
There are other games out there for the serious grognards. This game will satisfy roleplayers who long for the feel of the great WWI movies, who want to fight in the air but also want to have enough time left to roleplay their characters on the ground.