I have always been intrigued by the shifts in playstyle in games when players level up. This is most obvious in tabletop RPGs I think but it appears everywhere. Even in Blood Bowl there is a distinct early game where your players don't have block and you don't have many rerolls where the game is hilariously random and you knock your own team over constantly whereas the late game is much more predictable. The thing I have been wondering is whether or not people really want distinct game stages in their roleplaying games. Hobo was talking about this after he tested Heroes By Trade with me; specifically he didn't find that he was looking forward to high level play that much because there weren't huge and cool new things to acquire.
I have no objection to tiers of gameplay in some sense; fantasy stories often incorporate the idea of a group of people who start off doing trivial things like fighting some bandits or travelling through a dangerous forest who later on become super heroic and battle dragons while teleporting across the land. The trouble with these tiers I find is that an author has much greater control over the crazy powers that tend to dominate high level play. In a game with tremendous flexibility players tend to wreck carefully constructed worlds by using the tools at their disposal intelligently. They teleport into throne rooms and massacre kings, fly above armies incinerating them with fireballs, and sneak around permanently invisible.
The trouble is always the utility spells. Fireball is great and all but it is the flying and invisibility that really causes problems and teleport is nothing but a headache waiting to happen. I determined that in Heroes By Trade there would be utility Rituals but they are restricted by how fast you can heal the damage you take by using them and are designed to not get out of control. Characters slowly learn new Rituals and there isn't a breakpoint where they suddenly become supremely powerful or begin breaking the rules - it is a matter of slow, constant progression. Also Rituals are gated not by level but by investment so a relatively low level character who really wants to can learn the most powerful Rituals at the cost of being much less flexible in other ways. I don't want to let utility get out of control like DnD always did and that isn't going to change.
The other way people progress is raw combat power - bigger numbers. Characters avoid more attacks, take less damage, hit more often, do more damage, and have a wider selection of Powers as they level up. The difference is quite dramatic in total but it is a matter of incremental changes. +1 to this, -1 to that, one more option over here. I really don't want characters to be army killing engines and the system is designed to reflect that. A high level group could easily and indefinitely hold a small chokepoint against a huge number of infantry but if they end up surrounded by one hundred random people with longbows they are going to get wrecked very rapidly.
Heroes By Trade is very much designed around that idea of incremental changes rather than alternating 'dead levels' and massive new benefits but I think it is worth considering how I might add significant benefits of some kind that are available at higher levels. At first glance I am tempted to do this through class perks - at the moment each class picks one of three perks when they begin but I could add more perks at higher levels that characters can choose from. It would require making up a bunch more unique and interesting things for each class but it would certainly add something potent to look forward to.