Until April 1862, General Grant's ascendency in the American Union army has been relatively uneventful. But then came that fateful dawn when he and his 45,000-strong force was caught in a surprise attack by Confederate General Johnston and his army of the Mississippi. So began the Battle of Shiloh - two days that were to prove Grant's first real trial by fire.
In this latest wargame from experts Strategic Simulations, you have the chance to determine the outcome of this historic battle in the American Civil War.
Taking command of either army against the computer or a human opponent, you have the choice of playing at any of three levels: Introductory, intermediate or advanced.
There are fifteen turns in each game, each representing 90 minutes of real-time. A turn is made up of a number of phases which are played out over a two-level, 30 x 30 square-gridded, scrolling map of the battleground.
The terrain includes light and heavy woods, clearings, roads, ridges, creeks, ravines, swamps, orchards, streams, a ford, river, a sunken road and Shiloh Church.
The map can be viewed from long range - giving a strategic view of the whole battlefield - or you can zoom in to have a tactical look at an enlarged smaller area.
There are four types of unit used: Infantry, cavalry, gun boats and artillery. Each of these is rated for manpower - including guns if artillery - efficiency, morale, fatigue, weapon type, ammunition, and other factors. The units are distinguished on-screen by specific shapes and colours.
At the intermediate and advanced levels, the phases, in order of play, consist of command control, recovery or rally, reinforcement, followed by two sets of Confederate and Union operations and combat phases, with a mid-point recovery phase intervening and culminating in a victory determination phases.
On the eighth turn only, an end-of-day phase also comes into play.
Each phase offers a wide variety of options and the game is extremely flexible in play. It is not possible in a short review to do justice to the range of options, parameters and commands available and to the depth and complexity - and hence realism - of Shiloh.
But just to give you a flavour of the intricacies, let me list a few of the options open to you. You can elect to have certain units hidden from view, only becoming visible when moved adjacent to during an operation phase. This is particularly recommended if you want to realistically portray the fog of war.
Within any of the three overall complexity levels, you may pick from any of five difficulty levels. Level three is historical and makes no modification to either side.
The other levels affect the casualties inflicted in combat - one and two favour the Confederate player, four and five the Union. Ammunition supply, the efficiency of the units and the arrival of Union reinforcements may be varied and you can choose between a one- or the full two-day campaign.
In addition, a comprehensive range of commands allows the player to, among other things, display help menus, save and load games, toggle between tactical and strategic maps, remove units to view the underlying terrain, centre the map around a unit, build a level of fortification, and view all squares that the designated unit can fire into - the list goes on and on...
The game's algorithms are many and complex too. For example, each leader has a bonus rating that is modified randomly each turn. The effect this has is to make that command confused, indecisive, cautious or confident and this in turn affects the units.
Fortunately, the accompanying documentation, in the form of a glossy 60-plus page booklet, clearly sets out the instructions, background, complexities and ramifications.
The game is supplied in an attractively illustrated box and comes complete with a stiff map of the battlefield on the reverse of which is a handy reference guide.
Shiloh is sure to be greeted with delight by all wargaming fans. It is flexible enough for beginners to play at a fairly basic level but true sophistication and challenge really becomes apparent at the higher levels.
This is one that you can turn to again and again and represents excellent value for money. A must for all aficionados.