I have worked up an Event Cards chart, combining a standard 52 card deck with a cross-referenced chart for the following A&A games: Classic, Revised(2004), First Edition Pacific, and First Edition Europe. We have been playtesting them for several years now. For added realism, I use for the card deck a set of WW2 Aircraft Recognition cards, but an standard deck can be used. The events cover weather, technological improvements, production improvements, and one-time bonuses/windfalls. All are based on actual WW2 data and history. I anticipate selling the set through Historical Board Games along with my 6-player expansion rules for First Edition Pacific.
To use the deck, each player draws a card at the beginning of his turn, and the effects are checked and noted. Technology changes take effect immediately, and may be shared with any allies, is so noted on the chart. Weather effects take effect immediately, and last until the next turn of the drawing player. Production improvements and one time bonuses/windfalls take effect at the end of the players turn. Separate charts exist for the Allied and Axis player, and obviously, if an Axis player draws a card, that effect is denied to the Allied player. The Random Events have worked well in playtesting, and so far, both the Axis and the Allies have appeared to benefit equally.
I am working on adding Italy to the first edition Europe game, so I will need to revise the Europe chart to add Italy to it, and that will result in two separate charts for the Axis for Europe, and eventually Classic and Revised as well, along with the Global Rules that I am working on.