Maxperson
Morkus from Orkus
He's not? He's not deciding that, in this case, a crit doesn't happen when a specific number appears on a die? He's not deciding that, in this case, a tie goes to the defender rather than the attacker? How is that NOT a call on how a rule works?? Perhaps you could clarify what "making a call on how a rule works" means?
Umpires aren't changing anything. They are making a call on a situation, like when a DM makes a call on how a rule works. Fudging is an active change to the situation. The DM is not making a call on how a rule works. When a DM fudges, there was never any chance in the game world of the situation being any different. Additionally, specific beats general. In 5e fudging is a specific rule that supersedes the general combat rule regarding whether something hit or not. Lastly, the umpire would be cheating and the DM would not. There are clear differences between an umpire deliberately making the wrong call and a DM fudging.
Examples.
A player slides into base and the umpire makes a call on whether he's out or safe. Whether the umpire gets the call right or not, even if he deliberately calls it wrong, the truth of the matter can be shown by instant replay and/or the eyes of the crowd. The umpire has not changed reality with his ruling.
A DM fudges a hit into a miss. There was never any chance after the fudging for that attack to be a hit. In the game world the attack is a miss and nobody, even if they had instant replay, would see otherwise. The DM has changed reality with his ruling.
Except I was saying I *do* see some difference: house ruling is consistent and pre-defined, "rulings over rules" is neither consistent (because it is purely contextual) nor pre-defined (because it only happens when the DM decides to, not because of a specified trigger). Those are some pretty big distinctions to me!
A house rule is pre-defined. A ruling is not consistent and depends on context. Rulings Over Rules is what 5e calls the DM's ability to do both. The DM had the ability to do both granted to him by Rule 0 in previous editions. Rule 0 has just been put in nice new pretty packaging for 5e called Rulings Over Rules.
...how can you harm the party...without causing some amount of harm to at least one member of it? I don't understand.
Party and/or PC =/= player. You can harm a PC or party member without harming a player.