When thinking about Ragnarok and its identical vanilla human warbands, it reminded me how the first few games of a campaign (or specifically a Bloodbowl season) are a bit dull.
The reason? No one has gained any skills yet and so they they tend to be boring and vanilla. Usually then there is the fun patch of a few games until warbands pull ahead/fall behind and folk lose interest. It reminds me of a PC RTS - there's a boring stage where you build up your troops, a fun bit when you are actually fighting/the game is in the balance, and the 'mopping up' stage - also boring - when one side has obviously won and you are just razing their base. It's why I rarely play RTS (I'm only having fun 33% of the time) and also why I think campaign games can be improved.
Simple solution - allow everyone to have a roll on a skill/level-up chart BEFORE the campaign starts. In fact, we could take a leaf from RPGs and allow a themed warband i.e. I like how Bloodbowl (also Battle Companies) has "groups" of thematic skills. I think skills should be randomized to prevent OP combos being created but the player might choose say two skill 'trees' to roll on.
Also, warbands should level up more often. Every game! Why mess around with xp and kills. If you were in a battle, and you survived, you get to roll. Win or lose. Videogames give a constant stream of gratifying 'levels' and 'unlocks' - why should wargames choose to be more boring if we don't have to? MMOs often reward playtime over skill. Why not do the same?
This also simplifies things. Want to add a new warband 3 games in? Just make 3 extra skill rolls. Missed a game? Just make a skill roll and you don't fall behind power-wise.
But it's safer to just skip games and level up! Ok, perhaps roll to randomly wound =50% of the minis each game you skip. I.e. in battle companies you might randomly dice to select 5 of your 10-man warband, and roll a Str 4 wound against each.
TL:DR The cure to boring warbands: give thematic skill rolls BEFORE the game borrowing from RPGs; then 'level up' and award new skills/stats/toys consistently and often thereafter.
Campaigns often snowball quickly. Winning warbands quickly gain an insurmountable lead and a few losing games can make it almost pointless for some warbands to continue. This is because many campaigns punish losing several times. It's double jeopardy.
a) You probably have more wounded/dead, so you are disavdantaged/outnumbered in the future.
b) You gain less XP, so your heroes and mooks don't level up and are less powerful in the future.
c) You gain less gold, so you have less cool toys/weapons and are thus less powerful in the future
Losing is excessively punishing. It's like a soccer game where every time you concede a goal, you also get a player sent off. So let's make things less unpleasant, responding to a-b-c with fixes.
a) Give a free random unranked reinforcement. Perhaps if you lost a powerful model, you get several reinforcements equal to his points value or one just slightly less powerful i.e. if you lose a hero with 4 skill upgrades you get one with 3 skill upgrades. Losing your cool characterful model is punishment enough. Or - you actually always have more men than you can deploy. So then you choose which men and basically losing men just removes choice from the lineup. Like how a soccer team has a 25 man squad even though only 11 play. Losing a man injured doesn't mean you have to play with 10 men next game. If a model is injured it does not 'skip a game' - instead it has the option of playing while injured (say -1" speed and -1 to all dice rolls) and if he survives, he gets a bonus skill or +1 morale for being so gutsy.
b) Everyone who participates and lives (wounded or not) levels up.
c) More powerful warbands get less to simulate higher wages they pay out. Newly hired rookies are cheap.
Buuuh - I want to be rewarded for winning! Balancing is for special snowflakes who want participation awards! Competitive people like winning, period. They don't need extra incentives. They'll be counting their win-loss ratio anyway. All we are doing is trying to keep it fun for everyone by making the games themselves competitive. Imagine if in a pro sport, a loss meant you had to play with a man down all next game. As a spectacle, that would suck. It would quickly make the season of many teams both un-fun and uncompetitive. But this is common in most wargame campaigns.
Fully exploring campaign balance is beyond the scope of this post (I also want to talk about skills in a second) but I'll conclude by suggesting campaigns should have a set length. Leave them wanting more. I'd say ~6 games offhand - my reasoning; so you could play 2 games per night, and meet three times.
You could also allow some sort of structure - where you know you will likely play x sort of mission at least once. Kinda like a branching 'tree' of decisions - if/then - with some limited randomness thrown in so it is not too stale/predictable. I was noticing in MESBG when making a force it is wise to have a couple of fast units to seize objectives; if you know there is good chance of such a mission coming up you can balance warbands better.
I am also aware properly playtesting and balancing a campaign is almost impossible. Even a quick glance often shows most wargames rules themselves are badly balanced or poorly playtested. How are designers (especially indie ones) expected to play through campaigns many times and find every possible permutation? It would be a huge time sink. However, we can use common sense - such as not encouraging the "snowball effect" (above) - and trying to balance the game/skills itself, which IS reasonable.
TL:DR Balancing campaigns is almost impossible, but we can aim to counter the 'snowball effect' by not punishing losers in so many ways. When we do this, we may also gain the ability to 'catch up' newer warbands who missed a week or missed games/byes.
Speaking of MESBG, I've noticed the most commonly used spells are quite negative and dull. Transfix. Compel. Blind. These are boring skills. They all stop your opponent doing something.
Throwing fireballs? Cool. Having your mini freeze in place and do nothing for a round? Boring.
Example: I play a co-op PC game called Warframe with my kids. It's over-the-top robotic space ninja jedi with magic powers. The robots you control are crazy fun and powerful. You can backflip, slide and slash with katanas, dual-wielding machine guns while blasting hordes of foes with powerful space magic.
To make the game challenging, the devs came up with nullifier bubbles. These are bubbles around enemy units where your magic doesn't work. This is very unfun. Imagine being told "you are a robot space jedi but your jedi powers don't work most of the time. ....Instead of, say, giving enemies a powerful attack I could actively dodge, they just disable my toys. This is an example of a negative skill.
TL:DR Where possible skills should give you cool options and actions, not remove options and actions from opponents. Perhaps the latter is more realistic but it's less fun.
I think stat changes and skills should be low-key both in games AND campaigns. A quick way to eyeball the value of the skill or stat is to consider:
Skill Strength. (How powerful) In PC games, I recall a rule of thumb being any stat increase over 20% could be insurmountable for player skill. Especially if this applies to more than 1 stat. Having 20% more dps, 20% more speed and 20% more health is a huge advantage. In a wargame, this would translate to max +1 in a d6 based system or +2 in a d10 base system.
Skill Opportunity (How Often). A super powerful skill you can cast very rarely can be both (a) kinda unfun as you never get to use it and (b) a bit of a 'gotcha' for opponents. A weaker skill which you can (and will) use regularly both gives more flavour AND is more predictable for opponents.
Above I mentioned having semi-structured somewhat predictable campaigns of a set length. For example, if you know how often you are going to get a 'capture the objective' mission vs 'defend your baseline' it is easier to correctly value fast units.
I think 'opportunity' is the right place to mention terrain - wargames often don't specify how much or where. This is an oversight, as some skills and stats can differ hugely in value depending on the terrain.
"No penalty for moving in rough terrain/forests/water" -> meaningless if you are playing on a perfectly featureless board. I recall in LoTR:SBG goblins always did really well on my terrain-heavy boards, where their ability to freely scale vertical surfaces without penalty was quite powerful. However it was never a 'gotcha' - it was their main gimmick.
Infinity has very strong gun range and lethality, as well as opportunity (you can react to all enemy movements in LoS so lots of chances to shoot). A tall building or excessively large open LoS 'lanes' can mess up the whole game or make vast swathes of the board 'off limits.' It is a good example as its rules have diagrams explaining expected terrain coverage and also points out the effects.
Probably a final mention: that skills should be few, and 'shared.' I.e. there are no more than 20-30 skills in a common rulebook, using common tropes. There should be no excessive memorization or secret knowledge. Unlike Infinity, there should not be 5 rules all doing the same thing; instead they should be lumped together by effects (like Savage Worlds) i.e. super hearing and radar could both be lumped under "Supersenses" and have the same effect = automatically detecting/targeting any enemy within 8" regardless of LoS. Reducing the mental burden. A magical beam (be it heat, energy, or psychic force) would be called "beam" and have the same effect for all. Basically: skills should be predictable, shared knowledge. ME:SBG does this well - you expect a goblin to climb walls and a troll to toss enemies around - and the climbing and tossing rules are shared.
TL:DR Skills should be weak, and easy to use regularly. Shared knowledge for both players with no gotcha moments or unreasonable memorization requirements. Terrain and mission types need to be predictable (i.e. specified in the rules) in order for skills and stats to be reasonably balanced.
This is far from a thorough explanation of skills and campaigns (I've done this elswhere): just my current musings, based on messing around with Battle Companies and Ragnarok.