In a wargame hobby where no one thinks twice about doing the 33rd game on the Battle of the Bulge or the 50th Eastern Front wargame it's unusual when a reasonably popular topic seems to have a seminal game that doesn't see a redo. One of those topics, however, seems to be American Civil War tactical naval combat, which hasn't seen a serious simulation since Yaquinto's Ironclads, nearly 30 years ago.
Ironclads is a classic 1980s style full-bore board wargame in all its chart-heavy and procedure-dense glory. It depicts Civil War naval combat in excruciating detail, lovingly tracking every single shell from loading through exact hit location. There's drama aplenty with explosions, busted steam lines, toppled stacks and just about every other possible calamity accounted for.
By today's standards the game is rather slow moving, heavy on die rolls and charts and relies a lot on written orders. For the most part it works because Civil War Naval battles tended to involve just a few ships, bearing just a few guns each, and moving rather slowly.
The basic turn structure is the familiar one used in many tactical naval wargames. Players write a coded plot for how they will execute their available movement points. For example, a player with a ship that has five movement points could write down 2 L 1 R, which would order the ship to move two hexes forward, turn left, move 1 hex and then turn right. Firing is done after movement, based on a two D6 roll on a specific chart for each gun type with various modifiers for crew quality, battlefield conditions, target size and the like. If a hit is scored, additional rolls are made to determine exactly where the shot lands. The power of the shell is compared to the strength of the armor involved in that section and another roll determines how much damage is done to the armor. The general pattern is that repeated hits on the same section of the ship will gradually weaken it until penetrating hits become common, resulting is escalating damage.
There are rules covering just about every imaginable facet of Ironclad-era fighting, from boarding actions (rare) to floating mines (called "torpedoes" back then), forts, river obstructions, currents, shoals and more.
A year after Ironclads was first published Yaquinto came out with an expansion that added more ships and scenarios, including a more fleet actions and several battles from outside the Civil War. This was not entirely successful because the new battles tended to involve larger fleets with bigger, faster ships that were much more heavily armed, which stretched the limits of the game system.
Seven years later, 3W came out with Shot & Shell, which was billed as "completely compatible" with Ironclads, although also playable as a standalone game. Although no one from the original design team is listed in the game credits and it's unclear what permissions were granted, Shot & Shell is really a third expansion for Ironclads. There's no overlap in the scenarios and a conversion chart is provided for adapting the scenarios in the basic game and its expansion.
Shot & Shell cleans up the rules in many respects and adds a couple of important new rules concepts to deal with some of the problems in the original game.
One of those is an entirely new and detailed system for ground combat, which is much more detailed and realistic than the very sketchy rules in the original Ironclads. Several of the Shot & Shell scenarios involve. considerably more Army fighting than naval.
The second is a new way of handing situations where there are large numbers of guns being fired, as is common in the fleet actions. It essentially organizes the guns into groups and averages their effects on the targets. This streamlines a lot of the firing, while still allowing for cases of individual fire when needed.
Shot & Shell is a necessary adjunct to the base game.
There was also a reprint of the original Ironclads and the expansion set which changed the graphics (in a way that wasn't very popular) but otherwise made no significant rules changes, from what I've heard. Other than that, this topic hasn't really seen anything like Ironclads, a remarkable state of affairs.