but it would be phenomenally stupid to go into any sort of fight where you might lose. If there was only a 75% chance of winning, then no campaign would make it past the first day.
I didn't say there was no risk of failure. I just said that the chance of failure is substantially less than 25%. If you have a game where the PCs have a 25% chance of failure in every encounter, then you have a game where - on average - no party survives more than four encounters. Going by the suggested guidelines, you would suffer two TPKs every day, and nobody ever makes it to level 2.Designing an encounter with a 99% chance of success is not one that does a good job in challenging pcs.
...IME, campaigns where you are guaranteed to win every encounter are quite boring and are quickly abandoned.
In this case, "partial success" would be success with a cost - the party doesn't die, but they have to expend one or more spell slot or Hit Point. Most encounters would fall into that range. Each partial success increases the chance of failure over the course of the day.......To quote the current DMG (p.81), "An encounter has one of three possible outcomes: the characters succeed, the characters partly succeed or the characters fail. The encounter needs to account for all three possibilities, and the encounter needs to have consequences so that the players feel like their successes and failures matter."
I didn't say there was no risk of failure. I just said that the chance of failure is substantially less than 25%. If you have a game where the PCs have a 25% chance of failure in every encounter, then you have a game where - on average - no party survives more than four encounters. Going by the suggested guidelines, you would suffer two TPKs every day, and nobody ever makes it to level 2.
In this case, "partial success" would be success with a cost - the party doesn't die, but they have to expend one or more spell slot or Hit Point. Most encounters would fall into that range. Each partial success increases the chance of failure over the course of the day.
Total failure means everyone in the party dies. If you're using some other metric for what counts as a failure, then it would be possible to maintain a failure rate higher than 1% and still have some sort of lasting campaign, but you should really define your strange conditions beforehand.
Even if you didn't get weaker as the day went on, a failure rate of 25% is still way too high. Even if you abstract the whole combat out to a single die roll - just roll 1d4, and on a roll of 1 the party loses - then that roll of 1 would still happen eventually. When it takes 8 encounters to gain a level, it's unlikely that anyone would get to level 5, and fully 25% of all parties would die in their first encounter....A 25% chance of failure per encounter is challenging. However, it's not a cumulative factor ensuring a failure every four encounters. Arguing that successive encounters weaken characters is beside the point, proper encounters are designed with that reduced condition in mind. Assuming that the successive encounters fall on the same day.
Maybe you're asking the wrong question. If you can't come up with hard rules for what even counts as success or failure, then maybe you should ask how hard the players should need to work for their win: can you win by charging forward? or do you need some reasonable tactics? or do you need a good plan and a lot of luck, because one or the other won't cut it?...IME, it's a good idea to find out how tough players like their encounters. Which is what I am trying to do, in a more general community sense, in this poll.
I voted "other" - challenge difficulty is, in essence, a question of adventure pacing. Some should be hard, others easy.
I think most of us will find that we succeed *way* more often than 50% of the time. Are your PCs dying or running away every other encounter? No? Then they have more than a 50% chance of success.
Thus, what I believe Saelorn's angle was, his PC is going to try to setup the encounter so he has a 90% chance of success if he can. He's going to avoid or runaway from an encounter that he smells a low % of success.