"XP by for actions" means any sort of action, including -e.g.- killing stuff, not just achieving goals.
Yes.
Players don't get any reward if they solve encounters by doing something clever rather than employing canned modes of interaction (like combat or dialogue).
This depends largely on the encounter.
Doesn't really.
If you basically elect to to put a number of "tripwires" between the player and the objective, each triggering XP, you effectively resign yourself to one of two possibilities:
- Player somehow managing to bypass each and every one of thm, effectively getting punished by doing something "too" clever.
- Player aiming to specifically trigger more of them to get more XPs.
The correct way is to put the trigger on the objective itself instead if you just measure abstract advancement points (XP).
The only legitimate reason to be interested in how player achieves their goals for the purpose of advancement is when you're using this information to regulate the advancement itself - that's use based.
Also i wouldn't call combat as a "canned" mode of interaction - in many games building a character/party for combat is the main (and sometimes only) purpose.
Except it's not even combat that counts, just the killing blow. And yeah, it's pretty much canned interaction. Making an NPC die (in such way that the game can determine you to be the instigator) is hardly an open ended problem.
This sounds to me like saying that shooting demons in Doom is canned interaction :-P.
Doom is not an RPG. It doesn't really support gameplay beyond shooting shit while navigating levels and doesn't support character development either. You only have small and fixed amount of loot you can possibly accumulate to improve your capabilities.
This sounds like a bad setup, for a character to be able to sneak past the guy and get sneak XP their sneak skills must be checked against - similar for their dialogue skills and their combat skills. Characters should not be able to do all of the above at the same time.
Counterpoint:
Forcing characters to be one trick ponies yields deeply subar gameplay. Way worse than even letting them be a master of all trades by default.
If a character has only one tool in their toolbox, that means that no matter what obstacle they encounter it must be a nail to their hammer*.
So a combat oriented character needs to basically just hit whatever stands in their way, stealth oriented to sneak by everything, diplomancer to dialogue at everything.
This way you have effectively reduced your game to a bundle of three - an action (or tactical) combat game, stealth game and a visual novel, each reusing the same story and assets and each one sub-par due to using 1/3 of the budget it would normally have access to.
Slow. Clap.
Much better design is to let every character have a fairly substantial subset of all available tools as their toolbox, allowing meaningful decisions regarding which tools to use, how to combine them and how to compensate for the missing ones.
So using the examples above, instead of simple hulk smash, sneaky sneak that sneaks and rat diplomancer you'd have a warrior poet, deadly guerilla guy and silver-tongued rogue. Each having to decide which facet of their character to use at any given moment and how to combine them on a moment to moment basis.
*)
The alternative being, of course, designing the game such that not all (or perhaps even none) characters can complete it so that you can gloat at player not using the wiki beforehand.
There is, of course a place in the world for devs like this - this place is them straddling the business end of a massive, slowly rotating construction auger while begging for mercy.