Hriston
Dungeon Master of Middle-earth (He/him)
Those are two different things. RAW decides whether the visual requirements for the attempt are satisfied. The DM then decides success, failure, or in doubt. Only if in doubt is a roll asked for. Rolls are not dependent and satisfaction of the requirement.
The RAW doesn't say you can hide just so long as you're the tiniest bit obscured. The RAW gives the DM the duty of deciding if circumstances exist that allow the character to hide. If they do exist, the character can then hide. When the character hides, and the DM decides there's some uncertainty about whether he'll be found, the DM can ask the player to roll a Stealth check which is a contest between the character and anyone who tries to find him. If the character wins a contest, he prevents a creature from finding him. It would seem very odd to me for the DM to determine that circumstances are appropriate for hiding but then to declare the hider is automatically found by an observing creature. That seems more like an inappropriate circumstance to me.
This is a house rule. RAW includes auto failure as an outcome of the declared action by the player. If you are removing that option or moving it to another section of the rules, it's a house rule.
No it isn't. It's just hiding. The DM tells the player if hiding is possible. If the player hides after that, the DM shouldn't then decide it isn't possible.
This is flat out wrong. The DM is in fact letting the human try. He's declaring AFTER the attempt that it is a failure.
"When you try to hide, make a Dexterity (Stealth) check." The DEX check is synonymous with the attempt. Denying the check is the same as denying the attempt.