WHile not having actually played BoL...
- I've played many an equally simple game engine.
- I've seen reports of campaign play.
- I've read BoL.
BoL has character advancement options, and sufficient flexibility, to be able to sustain a 10-20 session campaign.
Assuming each session is a story¹, that's 2-3 Advancement points per session. (p. 40)
Which means 20-60 AP total.
Attribute raises cost current level + new level... Same for combat abilities. Note that 3 is maximum starting, but 5's are reasonably attainable, for both, without supernatural explanations.
Careers are cheaper... new level, minimum cost 1, to max of career level 5. A new career costs 1, remember?
So, let's assume joe is munchkined:
Strength 3 Brawl 0 Assassin 3
Agility 2 Melee 2 Soldier 1
Mind 0 Ranged -1
Appeal -1 Defense 3
Assuming Joe goes the supernatural defense route, he could, if the GM lets him, abuse it by spending 7 points on defense 4, then 9 more on defense 5, and maybe 11 more for defense 6... for 27 of those 60 absolute peak for a 20 session game. And he'll be HARD to hit.
Or, more reasonably, he could spend them to raise assassin and soldier both to 5: 4+5+2+3+4+5=23 points, plus another to level 2 (1+1+2) for the same 27 points.
Assuming the character survives, maxing out any two is about half the campaign.
That all said, an adventure (saga, as it's called in the rules) is not always a single session; 2 or even three sessions could be used readily. In which case, Joe's not even going to twist his character that far.
Things to note for campaign play:
- BOL envisions discrete downtime between adventures, and only 2-3 AP per downtime. And you have to "spend loot" to earn those...
- PC's grow in power, but not in worldly importance - you are not going to be a king just because you're buff.
- 20 Advancement Points is a lot... it's 10 novella's worth of growth... be stingy with that third point if shooting for 20 stories.
- Story ≠ session. Run a mission for several sessions to reduce the rapid growth, remembering that AP's are earned per mission, not per session.
¹ the assumption of 1 session per story is made for a worst case analysis. The rules imply more like 1-4 sessions per story, perhaps more.