One of the worst parts of 3E was how the rogue faced many monsters that their sneak attack didn't work against. Undead, aberrations, constructs.

When a player spends most of a session wondering why they came, you have a problem.

This is as opposed to the occasional monster which requires a change in tactics. That's fine. But you don't want to have every monster in a session immune to weapons or immune to magic. You want variety!

I sometimes feel that 4E and 5E went too much the other way - so many monsters have no significant immunities. (Except poison, which is very common).

One of the abilities I detest is "ignore resistance". And that's because it promotes one-trick ponies. I prefer it when the character can try something different when their main strategy doesn't work. The more the better (which is why I enjoy playing wizards).

And which brings us back to the rogue, who - in combat - becomes so reliant on sneak attack. What does a rogue do when they have to try something different?

I suspect that the answer isn't mechanical. It lies in the realm of the player and DM. Allowing the character to try different things, and adjudicating their results. The rogue likely has Acrobatics, Sleight of Hand and other skills. What can they do?

And not defined as "Acrobatics does this". Rather, what are the possibilities given the terrain and the potential of having a skill marked as "Acrobatics" on your sheet. What could you do?

The drawback of this is how much strain it puts on the DM and player - the DM to adjudicate, the player to come up with inventive solutions. So, you don't want this coming up every fight. Or possibly every session.