The game progresses in a sequence of phases:
Priority - Move - Shoot - Fight - End
I'll be going through what each of these phases is, but let me begin by saying that most of what happens in a game happens in the three bolded phases (Move, Shoot, and Fight).
1) Priority Phase
In general, it is better to have priority than to not have it, but at the beginning of the game (before units are close enough to attack each other or shoot at each other), it can be to a player's advantage to not have priority, as you can see how your opponent is lining up his forces. Ultimately, however, the player who has priority is determined by the roll of a dice, so this cannot always be predicted.
If two players tie for priority during the first roll of the game, the players can either roll again or roll a random dice to determine who wins (this will show up later), with the roll of a 1-3 favoring one opponent and a 4-6 favoring the other. If two players tie for priority on the second or subsequent rounds, ties for priority are given to the player who did not have it on the preceding turn. If the Elf player in the situation above rolled a 5 instead of a 4 and the Uruk player had priority on the previous turn, the Elves would now have priority.
2) Move Phase
3) Shoot Phase
The Shoot phase is pretty straight forward: units who have ranged weapons have the opportunity to shoot at enemy characters. How that works becomes a little more...complicated.
If there is ever a disagreement between the players as to whether the unit can be seen, roll a "random dice" to determine the result: on a 1-3, the unit cannot be seen and cannot be targeted by archery. On a 4-6, the unit is a legitimate target and can be targeted, but receives a special protection called "in-the-way," explained in a later post.
Third, the unit who is being shot at must be within the appropriate range of the shooter. Each bow has a certain range (in inches) that it can shoot and if the target is within this range, they can be shoot at. For example, a Crossbow and an Elf Bow have a range of 24". Orc Bows and Dwarf Bows have a range of 18" because they are smaller and can't send an arrow as far. Throwing weapons have a range of only 6", while other "special ranged weapons" have their ranges specified in their rules (like a Troll Chain or a hobbit-thrown rock). To measure this range, get a tape measure (or something that can measure the distance required) and measure from the front of the archer's base. If at least half of the target's base is covered by the distance, the target is a legitimate target (rules check on this - my mini-rulebook doesn't say: it could be that the whole base or simply a part of the base needs to be within range, but this is what I've always played with).
Once you've determined that you can shoot at an enemy unit, you get to roll to shoot at them. There are two parts to shooting at someone: hitting your target and wounding your target. Each unit has a "Shoot value," which takes the form of a "X+", where X is the minimum number that can be rolled in order for the arrow to hit his opponent. An Elf has a Shoot value of 3+, which means his arrow will hit his opponent on the dice roll of a 3, 4, 5, or 6. On a 1 or 2, we assume that the arrow went over his target's head or into the ground in front of him. In the picture above, the Elf rolls a 5, which successfully hits the Uruk-Hai Warrior he targeted.
The "To Wound" chart shows that an Elf Bow with Strength 3 will wound an Uruk-Hai Warrior with Defense 6 (Defense 5 + 1 for shield) on the roll of a 6. If the roll is met, the unit reduces his "Wounds" value by 1. If this falls to 0, the unit is removed as a casualty.
After rolling to see if you wound the unit, you may then fire with the other units that you have, determining if they are targeting a legitimate unit, rolling to hit, and then rolling to wound. An average unit will have a Bow with Strength 2, a range of 24", and a Shoot Value of 4+, so half of the shots that they fire will likely hit their targets and they will be asked to roll 5s or 6s in most cases to wound. So the likelihood that units fail to wound people with arrows is typically pretty high (though I've been surprised before).
If there is a tie in the rolls to win the fight, compare the "Fight Values" of the participants in the fight. A Dwarf's Fight Value is 4, while a Goblin's Fight Value is 2 (because Dwarves care about developing skilled fighters, while Goblins don't care much). If a Dwarf and a Goblin were to tie on their rolls, the Dwarf would win the tie because his Fight Value is higher. If the units had tied Fight values, roll a "random dice" to determine who wins, with a 1-3 favoring one side and a 4-6 favoring the other.
Pikes work in a similar way, except two pikes can be used to support a unit (either both touching the unit in combat OR creating a three-link train of sorts, shown above).
5) End Phase
Generally, nothing happens in this phase, but occasionally, the scenario you play in may have something that you do (bring on reinforcements, roll to end the game, etc.). If there is something, do it. Otherwise, proceed on to another round, beginning with Priority.
And that's it! All you need to know about the basic movements of the game. In later posts, I hope to explain how heroes work, how magic is cast, some important notes about terrain features, and tests that units need to take. In the meantime, I hope this was helpful!