One of the things I recently considered is how the game (and Space Crusade, for that matters) have a somewhat simple dice roll mechanism to determine who hits who and by how much. It's simple in the sense that 1 roll of the dice will determine the outcome of the attack action. However, by making a small change here, it could spice up combat a bit more by diversifying the various characters.
The idea is to split both the Attack roll and the Defence roll into two different components. Attack considers two aspects, after all: the ability to connect a weapon with the enemy in the first place and the damage potential that results from that connection in the second place. For that purpose, I would propose the introduction of two separate stats: Attack and Damage, which is given for each Hero. Let's say that the Barbarian (who relies on brute strength) has an Attack of 1, but a Damage of 3. The Elf (who is a graceful character) has the reverse, Attack of 3, but Damage of 1. The Dwarf isn't really good or bad at either and has an Attack and Damage of 2 and the Wizard would probably have an Attack of 2, but a Damage of 1. Weapons also have an inherent bonus to those for attack: let's say the Longsword has Attack +2 and Damage +1, whereas the Broadsword has Attack +1 and Damage +2.
Now how does this work? When the Barbarian equips a Broadsword, his effective stats become 2 for Attack and 5 for Damage. If the Elf were to equip it, he'd be at 4 for Attack, but only 3 for Damage. Now when they roll for combat, they roll a number of dice equal to their Attack to see if they can get a hit in. When they do hit the enemy, they roll for Damage to see just how much damage they do. Suppose they instead equip a Longsword instead, then the Barbarian would end up with an Attack score of 3 and Damage of 4, while the Elf ends up with an Attack score of 5, but a Damage of only 2. As you can see, the Barbarian has a lower chance to get a hit in than the Elf, but when he does, his damage output is higher.
Defense also considers two aspects: the first is the ability to avoid an enemy weapon from connecting to "self" and the second is the protection that reduces the incoming damage by a certain amount, should the enemy hit regardless. The first, damage avoidance, is simply a representation of how well the character is able to parry, block or dodge an enemy attack and when being attacked, a character has to roll a number of dice to see if they can avoid damage. When they do, they receive no damage at all. However, if they fail, they get hit by an enemy weapon, which then is going to deal damage. Damage can be absorbed in whatever armour is being worn, before actual blood is drawn. This Armour Class is a passive value, which is simply subtracted from the damage rolled by the enemy.
Let's say we have a Barbarian with a Chainmail and a Shield on the defense against an enemy attack. A Shield helps in preventing an attack from landing and thereby increases the number of dice used to defend against an enemy attack. If we take all Heroes to have 2 combat dice to use in defense, the Shield increases it by 1, for a total of 3 dice. This defense roll is opposed to the enemy attack roll to see if the attack lands a blow or not. Now suppose our unfortunate Barbarian failed to avoid the attack and gets hit: the enemy now rolls for damage, but due to the protection of the Chainmail he's wearing, damage is reduced. My suggestion would be to have an Armour Class of 1 for Leather Armour, 2 for Chainmail, 3 for Platemail (or perhaps even 4). So if the Monster rolled for 4 damage, the Barbarian would only receive 2 damage after subtracting the protection of the Chainmail.
Of course, Monsters that populate the game world also have these inherent values. Unlike Heroes, who can equip different weapons and armour, for Monsters the stats are simply static as they are now; they too have an Attack score, a Damage score, a Defense score and an Armour Class. An Orc for instance might have an Attack of 2 dice, Damage of 3 dice, Defense of 2 dice and 2 Armour Class. A Goblin might have as much as 4 Attack dice, but only 2 Damage die, 1 Defense die and only 1 Armour Class.
With this setup, Rock Skin could boost the target's Armour Class by 2 for example.
As always with suggestions like these, careful balancing tests would be needed to see what the actual values and number of dice would need to be; for instance, a tough enemy like a Chaos Warrior would have an Armour Class of 3, which means a character could only harm it if they had at least a Strength of 3 (after weapon bonus); as such, Damage probably needs to be higher across the board.
Thoughts?
Edit: made some consistency changes.
Also, while this post is written with HeroQuest in mind, something similar might work for Space Crusade - which could provide a significant boost to melee weapons there, making them worthwhile next to the various ranged weapons.