Damage of skills (effect) is tied to power, crit chance, crit damage (stats). Damage from conditions (effect) is tied to, well, condition damage (stat).
Boon/condition duration (effect) is directly derived from the skill (source) and the boon/condition duration statistic (stat).
There is a whole lot of effects not tied to anything but the source.
When you apply aegis, only the skill is taken into consideration (and, perhaps, some traits which enhance the effect, but they work as secondary source with a secondary effect that trigger on the skill usage). When you shout “Retreat!”, the duration of swiftness and aegis is based on your boon duration (stat), but the boon effects are static; it’s always 33% extra speed and one guaranteed block.
What if swiftness, in its flat form, increased speed by 10%, and then more after meeting certain stat criteria – with 30% boon duration, it would become 20%, with 50% boon duration – 33%? What if aegis wouldn’t provide a guaranteed block but a 50%-chance block without meeting a certain level of toughness?
Considering it further – what if chill power was based on condition damage? It would still stack in duration – do not misinterpret that part. But it currently reduces the speed and skill recharge by 66% regardless of your stats, based solely on the skill you use to apply chill; what if with base condition damage it was only 15%, then increasing as condition damage increases?
What if stuns and dazes in their duration and/or chance of landing were tied to a defensive stat? Or even to both vitality and toughness.
What if cc used by high-toughness toons removed more than one stack of defiance a time?
What if protection from someone running pure zerker build wasn’t 33% damage reduction, but 10% at most?
If blinds weren’t a sure cc unless you have some level of condition damage and/or toughness and/or vitality – but then, consequently, with high enough stats, they landed with up to 50% success on bosses with defiance?
This is mainly for PvE, but if carefully balanced – perhaps with reworking some stats and/or introducing a new one – it might be viable in both other formats as well.
I am not sure how good an idea it is myself, truth be told. It would allow zerkers to keep their high dps output but nerf their cc and buff potential, thus nerfing their survivability and boon uptime; it wouldn’t make tanky setups faster than well-played zerker groups, but considerably more useful. Free mixing of condition/toughness/zerker players would be more encouraged, albeit it would not be necessary to achieve any goal – full zerker teams would still be able to do stuff, as full tanky parties, and full condi parties, with all their respective (dis)advantages.
The meta would shift, favouring bringing one or two non-zerker people into the team, as the min/maxing would move from pure damage that can sustain itself via defensive and cc effects (not tied to anything, thus working with its full potential on zerker now) towards a kind of trinity – but it still would not be required, just as running 5man zerker is not required now to complete content (from the design perspective, that is).
On the other hand, it might make cc/boon-stacking teams even more effective than zerkers currently are. It certainly would require careful balancing within a big overhaul of the game mechanics, but if introduced in bits rather than one big update, it shouldn’t be that felt by the players and it would be monitored quite easily.
The planning and testing workload would be huge, though, and even then i am not sure if the final effect would be worth it, especially compared to other options of balancing things out.
Consider it just food for thought.
The effect-stat ties, like swiftness with boon duration at the beginning, are only raw examples to illustrate the idea, in no way suggested as be the way to go.