BEGINNING A MAP
Generally, the map is the all-important factor in deciding how the game will play out. Map size, amount of loose resources, number of mines and towns should all be considered when planning ahead. As a general rule, small, resource-scarce maps favor might-oriented strategies, since there is little time (and resources) to upgrade your Mage Guild before the fighting begins. On larger boards, magic is the key to a successful campaign. On such maps, especially in the late stages of the game, mobility is paramount. Spells such as Town Portal, Dimension Door, Fly, and even Water Walk will let you get around the map more efficiently.
The same principle applies to the economy vs. creature generators issue, where smaller maps are more condusive to battle readiness, while larger ones tend to be territorial races with superior economies being able to field more fearsome armies.
It's a good idea to choose maps which suit your style of play (this is particularly true when facing human opponents). For example, micromanagement wizards will like smaller maps, where building orders are crucial. Larger scenarios tend to bring out a player's skill better, because long-term planning and careful character development require considerable gaming insight.
The following sections will attempt to guide you through the three major stages of the game.
Depending on the scenario settings, you should start by hiring several heroes right away. Select a hero who you'd like to develop over the course of the game and transfer all the available troops from the other heroes to him/her. Try not to mix too many town types, though. This will be your wandering hero. Before you send him/her off, make sure to either build a creature dwelling to boost your army even further or, if he/she is a might hero, get a Mage Guild to purchase a magic book. When you're all set, pick a direction and start exploring. Fight any neutral army camp you think you can beat without many casualties and take the experience from any treasure chest you encounter (unless you really REALLY need the money). Go as far as you can in any given direction and then pick a new one. Don't be afraid to stray far, you can always run away if things get hairy. If you're lucky, you can keep at it for a good month or so without feeling the need to go back for reinforcements.
As soon as you send your exploration hero out, send everyone else to explore your immediate surroundings. Collect resources, get money out of treasure chests, visit map sites, etc.. Start building your town up. Select a second hero you'd like to advance in levels and put him in charge of your town. Arm him with the town's populace and send him/her out to clear out mines, invade nearby towns, and battle neutral camps. Don't stray too far from your base with this one, though, he/she may be needed to defend against enemy incursions.
At this point you have set up a dynamic game flow, with your wandering hero out exploring the map and getting stronger, your base hero taming your surroundings, and your other heroes gathering resources and creatures from external map locations. On a medium or larger sized map with hard difficulty settings the mid game starts approximately by the end of month one. By this time your town should be upgraded up to at least a city hall with a castle and a basic level 7 creature generator.
You can start thinking about bringing your wandering hero back to the main base, unless you established a new one along the way. The mid game is all about assessing the map as a whole. By this I mean finding important sites such as a heavily-guarded super artifact, an important map location (Dragon Utopias, Pyramids, Banks and Caches, etc.), an accessible enemy town, and other things which may potentially play a major role later on. You should really concentrate on exploring/conquering territory at this point. Be as aggressive as you can afford to be. Don't turtle with hopes of amassing a huge army from what you currently have, because your enemies are surely doing the same. Seize the advantage by having more than what they have.
This part deals with finding your enemies and deciding on the best course of action in handling them. In order to learn more about what you're about to face, send numerous (and expendable) scouts deep into enemy territory to remove every inch of shroud they can before expiring. Reconnaissance is very important in making the right strategical decisions at any given point of the game. It really depends on the particular game, but it usually comes down to who's the most prepared at the point of conflict. For example, a seemingly weak enemy could field a huge army in a matter of days, if his/her economy can allow it. It is a good idea to learn as much as you possibly can about your opponent before making a move. Checking your thieves guild for clues on a regular basis is a good way of keeping track of enemy strength or even his intentions.
As far as engaging the enemy goes, you can experiment with a number of things like hit and runs to weaken your opponents resistance capabilities. Offensive magic specialists such as Solmyr and Deemer, armed with a few fast and sturdy creature stacks, can execute quick raids without too much trouble. Another long time favorite strategy is sacking lighty-defended towns late in the week. When preparing an all-out assault, try sending more than one strong hero into battle. In case the first hero fails, that will enable you to finish off your opponent before he/she has a chance to recover.
A little word of advise: never attack an opponent of comparative strength while he/she is behind castle walls, unless the situation really calls for it. Town defenses can play a huge role in determining the outcome of a battle. If you ever find yourself in a situation where the enemy turtles inside his town, it is better to exercise a containment police rather than charging the town right away. By containment I mean keeping a strong hero near the enemy town, while others steal mines and other locations flagged by the enemy. This will, in time, weaken you enemy and you can maintain your own army's strength by bringing reinforcements to your main hero.
Thanks to The Nether Gods team for the contents of this page!