I understand the concept behind milestones, and what the DMG recommends. I was planning to use old fashioned XP-per-encounter for my campaign, but the more I read the more I prefer milestones.

My question is, how do I handle milestones in a sandbox setting? In a more linear story it is easier, as I have set points of the plot where the characters can level up. In a sandbox, however, players can ignore the main story line in favour of the smaller quests and villains, each of which is insignificant in the grand scheme of things. How do I handle milestones in this case?

An example to clarify

I would like to run a campaign where something big is happening in the world (e.g. gods are about to go to war, or 2 different nations). The PCs will be in that world and could possibly be involved in this overarching "incident". I, as DM, could throw something their way to incentivise them to get involved (e.g. they find something one of the sides is looking for), but they would be free to ignore it or follow their own backstories (while the overarching "incident" is moving along) and they can get involved later.

Milestones began as road signs:

A milestone is one of a series of numbered markers placed along a road or boundary at intervals of one mile or occasionally, parts of a mile. Wikipedia

So they make no sense where there is no road to follow. In 100% sandbox without "main storyline" or "grand scheme of things", they make no sense.

In your game, there is main plot, so for "purists" it may not qualify as sandbox, but milestones may work.

I'm a DM in a game where there is grand scheme, and there is a lot of freedom for PC. Campaign books are doing a really good job by mixing XP system and milestone system. They do it by:

1. Providing XP for achieving milestones


2. Stating at some points that, for example, "PCs should be at least level 7 now"

If XP set for a milestone is not enough to get characters to level 7, I simply give them level 7. If it is enough and more, or if they are already at level 7 or above, I give them XP.

In theory there is a risk that they would get two levels, if they were still level 5 when they hit level 7 milestone. In practice, that never happened to us.

We are playing like that for two years now and we had no major issues.

This is a mix of rules found on page 261 of Dungeon Master Guide - XP for milestones follows up "Milestones" section, and "character should be level X" is more like "Level Advancement without XP" -> "Story-Based advancement" found there. So this is not RAW, but playable and gives progression similar to RAW ones.

I run a very sandboxed campaign, and I use a modified form of milestone XP. The thing is, as a DM, you can decide people level up at any time. For me, that's too much power and a lot to keep track of. In previous sandboxy games, I wound up with my players leveling up at completely random intervals, which satisfied neither myself or them. So, for this exact purpose, I came up with a modified milestone chart to keep track of them.

I did some amount of math and an awful lot of guessing, and came up with a table that was based on the XP leveling table, but, instead, was broken into how many sessions need to occur for each level. At no point will it take more than 8 sessions for the party to level up, simply because I felt that that was as long as my players would tolerate before getting restless.

Unfortunately, the markup used here doesn't appear to support tables, so here's a screenshot of what I came up with:

I found this by deciding that I wanted the trip from level one to level two should be 2 sessions, then went through and calculated the proportions of the XP needed for all the other levels to the XP needed to get from level one to level two. This left me with some egregious numbers, and, figuring that higher level enemies give higher XP, I pared everything down by a lot, while maintaining some of the same general ratios. As discussed in this question, the XP increases unevenly throughout the levels. In this answer to the same question, GMNoob reports that this was an intentional choice in the design of the game, so I've opted to maintain that aspect.

I have been running with this for nearly a year so far, and it's been going great. I prefer it over just choosing big moments, because sometimes those crop up very frequently and sometimes they crop up very rarely. It also simplifies the numbers, and gives me an easy way to reward extra "XP". For example, my party recently faced off against an encounter literally 3x the threshold for deadly for their level, and for their clever thinking to get out of it, I noted that they'll level up a session earlier than my chart says. This particular encounter was prompted by one player's backstory, but then the very next session, they dove into an equally in-depth adventure based in a different player's backstory-- so, by milestones, it gets sort of wibbly.

As you can probably guess from this anecdote, I'm running a sandbox where there's truly an ability for the players to end up in situations that they aren't of an appropriate level for, if they do dumb things, but I also have certain specific milestones when specific things become unlocked-- for my campaign, these are the levels highlighted in yellow.

This system, in my experience, has maintained the designer intent with the XP chart, while also allowing for some of the flexibility of milestones. Personally, I find it easier to deal with smaller numbers than larger ones, which means I can more easily say "This particular action is worth about 1/4th of a level" when I know that 1/4th of a level is precisely one session, for example.

As a GM, you should always have a general understanding of what is going on in the world as well as what the party will do next. That does not mean you will be right 100% of the time, the party will sometimes veer off track, but there should always be some form of story.

D&D really is interactive story telling. As the GM, you set up this story and decide how PC's interaction affect the world and NPCs around them. When thinking about milestone experience, there are a couple things to consider:

1. How big is the experience gap between level X and Y?


2. How tough are the encounters?

Because you should have a general understanding of where the story is going most of the time, it should be easy to identify major story arches. What I usually do is determine major story points. Based on what would need to happen, I try to envision what it will take to complete that story arch. I can usually come up with a rough number for how many encounters what will take.

Just because the campaign is sandbox does not mean there is not main story and story arches. For instance, if the PCs decide they want to go investigate a cave where some miners have gone missing, that is a story arch. When you build story arch, you should have a general idea of how difficult it will be. That is usually enough to decide if they should get a level from that.

If you don't believe this story was enough for a level, come up with an xp number based on the encounters they did, then just keep a running total on your end. For every story they complete, give them xp until they level up.

Use milestones for achievements

tl;dr Use milestones for the significant achievements of the party. Scale the size of the required achievement with party level.

Why I prefer milestones

Personally I hate XP levelling in story-focused games. It feels at odds with the otherwise narrative driven plot. For example:

I killed enough goblins so now I can cast fireball

is much less meaningful to me than

I saved a town from a goblin horde, in the process I learned about myself and discovered new abilities.

Mechanically it's the same reward for the same actions but thematically it is very different. Additionally milestones mean that if you accidentally killed 1 too few goblins you still get the cool narrative moment of levelling up instead of the let down of being just short at the end of the adventure.

How I award milestones

In my campaign the PCs have to earn their milestones. They have too do something worthy of advancement, a task or quest that seemed beyond them before. Some examples from my current campaign:

• Level 1: Escaped Prison


• Level 2: Retrieved a cure to save a small town.


• Level 3: Defeated the local villain who had previously imprisoned them


• Level 4: Successfully reached a dangerous distant location


• Level 5: Completed a major quest to prevent weapons of war falling in to the wrong hands


• Level 6 (planned): Save a town being raided by Orcs during a war


• Level 7 (planned): Stop the war

At each level the size and difficulty of the achievement required increases. By doing this my players feel rewarded for accomplishing major goals. It also encourages them to take on bigger and more dangerous adventures. By requiring each achievement to be bigger than the last the players can't spend months going around completing sides quests in order to out-level the main campaign. Savings a small town was a level 2 quest, it is no longer a big enough achievement to gain advancement.

Running in a sandbox

Similar to you I run in a sandbox world were the players and free to go where they like and do what they wish. This can make it difficult to determine which missions they will take on and which should be rewarded with milestones. I handle this with my rule from above, each achievement must be bigger than the last.

If my players choose to abandon the current quest-line my planned milestones above would become irrelevant. Instead I would replace them with new ones of similar status. These alternate achievements can either be entirely new ones or ones you have initially planned for a later level and scaled down accordingly. For example:

• Level 6 (alternate): End the siege on the wizards' assembly


• Level 7 (alternate): Rescue the king's daughter

The idea is that any time the player's feel they have taken a step forward as adventure; completed a grand quest, overcome an treacherous foe or obtained a dangerous mcguffin they should be rewarded for it.

How many and how often to give out milestones

I'm going to take a bit of a different tack here to the other answers. Most DM's use milestones to approximate the XP level system just without the tricky math. Blue Caboose's answer is good if that is the kind of system you want. It isn't how or why I use milestones however.

To decide how many and how often to give out milestones you need a rough idea of your main story arc, or at least an end goal for where the party might end up. This will likely shift and change based on the decisions they make but a rough idea is good enough. You want to know roughly what level you want your campaign to end, and how much story you want to tell along the way.

Break up your story into smaller arcs and determine which points will be milestone achievements. Overcoming major minions of a BBEG is a common one for me. (See level 3 above). My campaign is going to level 20 and I have a lot of story to tell so they are levelling fairly slowly (~10 sessions per level), two years in and they are still at level 5.

'Punishing' failure

One (arguable) downside of this system is that it effectively 'punishes' failure and tactical retreats. When the bad-guy gets away or they fail to achieve their goals their is no participation trophy for their efforts. They get nothing but the loot they take with them, no XP buffs to make it easier next time. In fact my enemies often get more difficult if the players faced them once and failed to defeat them.

Does this sometimes leave the players without a level for an extended period? Yes, my party were at level 3 for ~20 sessions, they were frustrated by their lack of progress but so were their characters. To me the increased immersion of sharing that frustration with their character was worth the trade off of cool new abilities.

My players agree. They feel it would have cheapened the experience were I to just give them the level because they had gone so long without one. They didn't feel like their characters deserved rewards after failing/running from several missions. It made the level mean so much more when they finally achieved it.