Should I treat exploring for over 8 hours in a cave
As a “Forced March”?
Using the Forced March rules requiring CON Saves every hour
With DC progressively getting higher each hour
Before the party completes a Short Rest?
The Forced March rules come up starting after 8 hours of marching, not during. You would start to worry about it only when getting to hour 9.
And it depends on the size of the cave - for certain, yes, the travel pace rules can and do apply to underland travel in the Underdark, for example. If the party is going to spend hours of narrative time walking, use the rules for walking in narrative time, i.e. travel pace and forced marches and such.
If the players take a long rest, start their day by going into the cave, explore it vigorously for 8 hours, then call it quits, that doesn't feel like a forced march situation to me. Now if your cave was a particularly hostile environment, it's certainly possible, but based on the information you gave so far, I don't feel like that would cause exhaustion within 8 hours.
I wouldn't. A forced march is a very different situation from exploring. When exploring, you're not constantly on the move. You stop, update the map. There are probably short breaks for some of the characters often. When you do move, you move cautiously.
The constraining mechanic on exploring is encounters. The continuous wear on the characters' resources eventually forces them to fall back. Under those circumstances, you might actually be able to achieve the 6-8 encounters between long rests that the D&D encounter-balancing rules are purportedly based on.
Depending on the nature of the area they're exploring, that is a definite possibility. Granted, exploring an area like a cave or a dungeon or a mansion or a forest may provide more opportunities for rest and snacking than a forced march would. However, if you're exploring an area that is (or is expected to be) exceedingly dangerous, then the stress of constant vigilance, and the amperage of constant adrenaline output could certainly have the same wear-and-tear effects on your body and mind as a forced march. Nine hours of constant march down a road in a known environment will wear you down physically. But spending nine hours exploring barrow crypts where your untimely death could be lurking in any of the shadows around you will wear you down not just physically, but mentally as well.
A Con save should be called for whenever your body is pushed beyond its normal limits. But you're not just muscle and bone. Your brain, your heart, your eyes, your nerves... they can be pushed beyond their limits too during a prolonged exploration.
Ultimately, it's up to the DM's judgment on a case by case basis.
Should I treat exploring for over 8 hours in a cave
As a “Forced March”?
Using the Forced March rules requiring CON Saves every hour
With DC progressively getting higher each hour
Before the party completes a Short Rest?
The Forced March rules come up starting after 8 hours of marching, not during. You would start to worry about it only when getting to hour 9.
And it depends on the size of the cave - for certain, yes, the travel pace rules can and do apply to underland travel in the Underdark, for example. If the party is going to spend hours of narrative time walking, use the rules for walking in narrative time, i.e. travel pace and forced marches and such.
If the players take a long rest, start their day by going into the cave, explore it vigorously for 8 hours, then call it quits, that doesn't feel like a forced march situation to me. Now if your cave was a particularly hostile environment, it's certainly possible, but based on the information you gave so far, I don't feel like that would cause exhaustion within 8 hours.
"Not all those who wander are lost"
I wouldn't. A forced march is a very different situation from exploring. When exploring, you're not constantly on the move. You stop, update the map. There are probably short breaks for some of the characters often. When you do move, you move cautiously.
The constraining mechanic on exploring is encounters. The continuous wear on the characters' resources eventually forces them to fall back. Under those circumstances, you might actually be able to achieve the 6-8 encounters between long rests that the D&D encounter-balancing rules are purportedly based on.
In regards to Encounters
I’ve been running them the way I believe I’ve seen the game mechanic in the DMG:
18-20 roll on a d20 = Random Encounter
Regarding the CON Save / “Forced March” after 8 hours of exploring
I figured exhaustion would ensue because what if my Players decide to keep exploring for another 5-10 hours?
Also, I’m tracking Food & Water intake every 24 hours so looking to work this in as well
So you think the PCs should just be tired but not exhausted after the 8 hour mark?
At what point would a risk of exhaustion kick in?
How many hours without resting would be a good time for them to eventually do CON Saves when exploring?
Depending on the nature of the area they're exploring, that is a definite possibility. Granted, exploring an area like a cave or a dungeon or a mansion or a forest may provide more opportunities for rest and snacking than a forced march would. However, if you're exploring an area that is (or is expected to be) exceedingly dangerous, then the stress of constant vigilance, and the amperage of constant adrenaline output could certainly have the same wear-and-tear effects on your body and mind as a forced march. Nine hours of constant march down a road in a known environment will wear you down physically. But spending nine hours exploring barrow crypts where your untimely death could be lurking in any of the shadows around you will wear you down not just physically, but mentally as well.
A Con save should be called for whenever your body is pushed beyond its normal limits. But you're not just muscle and bone. Your brain, your heart, your eyes, your nerves... they can be pushed beyond their limits too during a prolonged exploration.
Ultimately, it's up to the DM's judgment on a case by case basis.
Just my 2 c.p.
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