It's 1:1 though, because the medium encounter budget is for one player. So presumably if you have three monsters, you would have four PC's, thus the advancement rate would actually be slightly lower. Unless you're talking about 3 monsters per player?
I worked out somewhere else on another post that basically for a party of four:
- An easy encounter is one monster that is 0.5 * the average CR of the party;
- Medium is one monster that is 1 * the average CR of the party;
- Hard is 1.5;
- Deadly is 2;
For example, a deadly encounter for a 10th level party is 2*CR10 monsters. It's not *exactly* integers like that, but it's close enough to be linear.
This would mean that if you throw nothing but deadly encounters at your party (or 2 monsters of their average level, every encounter) then they would level twice as fast. Hard they would level 1.5 times as fast. Easy they would level half as slow.
So when you consider that most parties are probably facing more hard & deadly encounters than easy, AND also potentially gaining quest completion XP, they'll probably level even faster. Is that what you are basically saying?![]()
Regardless of how deadly the encounter is, the multiplier is keyed off of the number of monsters and PCs. To borrow 4 members of your 13th level party:
If the 4 players fight 1 CR 13 monster at 10,000 xp, then the encounter budget multiplier is 1. The 10,000 adjusted encounter xp is a medium encounter for the party. The 10,000 XP is divided among the party, and each PC receives 2,500xp
If the 4 players fight 3 CR 5 monsters at 1,800 xp each, then the encounter budget multiplier is 2. The 5,400 xp for the 3 monsters is adjusted to 10,800 xp for the purposes of determining encounter difficulty only. The original 5,400 xp for the 3 monsters is divided among the party, and each PC receives 1,350 xp.