[RPG] How many hours to go from level 1 to 10 in a campaign

Let's do some math, assuming we take an average 4 people party, starting at 0XP.

The Encounter Budget Chart helpfully tells us, that every encounter should contain at best 400 XP for the first level, 500 XP for level 2 etc. The tables for for the budgets has a few jumps, but that doesn't help with speed... yet. It only gives us XP/Encounter, which can be calculated into the XP per player and hour, which we ultimately need to get the time per level.

$$\frac{{XP}_{Group}}{Encounter}\times\frac {Encounter} {Encountertime\text{ [in h]}}=\frac{{XP}_{Group}}{\text h}=N_{Players} \frac{{XP}_{Player}}{h}$$

Filling in with a 4 player group, 75 minutes per Encounter (=1.25 hours), this gives $$\frac {{XP}_{Group}} {4 \times 1.25\text h}= {{XP}_{Player}}$$

Now, how much XP we need? Character advancement table time! Ok, 1000 for level 1, 2250 for level 2 etc.

Let's have FUN with MATH! OR... we do it easy: Let's make an excel table! or rather, a Google Spreadsheet!

112.5 hours of encounters to gain level 10, it is reached in Session 28, assuming 4 hour per session are dedicated to encounters and encounters can be seamlessly split up; nobody ever comes late, ruleslawyers, investigates abandoned wells^* or just derails the plot; interludes are part of the encounters and take up no extra time; etc.

All in all, I estimate that these 112.5 hours of encounters to level 10 will be overshot by at least 50% for interludes, Plot reasons, prolonged battles and just bad mood, etc.

Now, the tricky part: we have 100-150 total hours available. One of 5 hours is dedicated to arrival and cleanup, so 20% loss. That is 80 to 120 hours available... That makes it a bit tight, leaving at worst halfway between Level 7 and 8, and in best leaving two sessions after acquiring level 10 - as long as the estimated 1.25 hours are fixed.

Now, a short experiment of what happens if we manage to drop encounter time to 60 minutes flat! Hours per level... drop to 10 hours of encounter per level, and we only need 90 hours of encounters for level 10. In THAT case, you will very likely manage it.

Conclusion

To squeeze in the 10 levels into the 150 hours of sessions (of which about 20% are dedicated to arrival and cleanup) and reach level 10, you might want to fix one or more of the three screws that are relevant to the calculation:

• Tweak XP needed per level downwards
• Give more XP per encounter than calculated per player (netting more \${XP}_{Player}\$)
• Achieve faster encounter times (however you manage that - it directly increases the XP/h rate)

As an alternative: switch to milestone Level-Ups.

* The story behind the well goes rougly like this:

^{I was GMing a campaign. After a night rest in the wilds, the group encountered a hole in the ground the next morning. It was intended as a simple "fail your perception and reflex roll, and you take some damage" at first. Nobody fell, but they started to investigate the abandoned well without walls with increasing stubbornness and despite my maniac laughter (were they expecting a TPK because of that?!). Over their discussions they went from throwing mere stones to tossing their bard into it, almost forgetting a tether for the later. I didn't budge, it stayed a deep hole in the ground with black rock lining and water at the floor deep below, and it didn't wanted to tell any of them anything because none had Knowledges or Professions that could be applied. But they had lots of fun doing it for two hours, when I finally told them "Guys, do you want to continue searching or do you want to continue the adventure?!"}