Of course not. The Rules(what the DM decides for his game), absolutely shouldn't be ignored.
There aren't any 'rules' in the book, it's all just good advice for most games. Unless, of course, the DM wants to do something drastically different or even just a little different.
Right, but we have to base the discussion on something when discussing the rules, which would be the written rules. Like Joe said, I don't think anyone is saying the DM cannot simply change the rules, but we can't just base a discussion on the assumption of changed rules. Written rules are discussed as written to get a better idea of what might need changed and why.
For me, I wouldn't change the -5/+10 feats. They are there to increase damage on damage builds and if they increase that damage they are fulfilling the intent. Zard's concern is more in how much of an increase there is and if that's acceptable. I can see that as a legitimate concern when first examining the increase, but Zard sees an increase in conjunction with accuracy bonuses. Without those accuracy bonuses, -5/+10 feats don't provide big damage boosts and often cost damage in taking that penalty to hit. That tells me the issue isn't with the -5/+10 and it's more of an example of the potency that comes with accuracy bonuses in a system that has bounded accuracy where -5 is a big penalty. -5 is the equivalent of max ability modifier or very high level proficiency bonus and it is a big penalty.
That begs the question that if the -5/+10 isn't a good investment without the accuracy bonuses then why are we looking at -5/+10 instead of the accuracy bonuses, or possibly the applicable bonus attacks (like pole arm master) that can apply it additionally. Exclusively applying either pole arm master or great weapon master but not both simultaneously is where that leads, and you are correct in that it can be a solution if one assumes there is an issue to solve. I don't agree that there is because more damage is working as intended, but also, we're still looking at that big -5 penalty that's being offset by accuracy bonuses that creates the damage with both feats (which is a big investment and also part of why I'm not convinced of a problem).
If root cause analysis of a proposed issue leads us to accuracy bonuses when we look at sharpshooter, great weapon master, or great weapon master plus pole arm master then it makes more sense to look at accuracy as something a DM might rule adjustments. However, the intent appears to be that accuracy bonuses are meant to be big enhancers because it's the main offensive contribution to a couple of classes. Any changes to accuracy negatively impacts those classes and detracts from what appears to be meant to be a very strong ability.
The easiest thing for any DM to do would be to make a change and we all understand that, but the ability to change the rules doesn't actually change the default rules, and discussing them gives more insight into what to change (or decide not to change) and why.
It's all good.
