Influence of XP Design on Player Motivation

I've been thinking a lot about game design lately, and one topic that I keep coming back to is character growth and player incentives - namely, how the character growth system (experience points (XP), generally) can influence player behavior through the desire to advance the character.

I'll be writing from the perspective of tabletop design, as it's what I'm most familiar with but the principles apply to video games and board games as well. There are several lessons to be pulled from video game design as well, which I'll touch on. There's an almost universal fundamental design principle lurking inside - how does game design interact with psychology to provide an experience that's rewarding to the player, and how do those systems influence player behavior through their incentives.

Game Design Loops

Every game has one or more loops that the player will interact with that is core to the gameplay experience. There are usually several of these in a given game (even the simplest games), and all of them follow a similar pattern: challenge -> solution -> reward. A very basic example in many tabletop RPGs is a combat XP loop:

1. Encounter a hostile creature(s)
2. Defeat that creature or creatures through violence, spells, swords, improvised weapons, etc.
3. Receive XP from defeating said creature(s) and use that to gain more ability to defeat hostile creatures.

There's frequently a secondary loop embedded in that first one - gain the treasure that monster was hoarding -> use that treasure to buy stronger gear -> go find more treasure.

This is true of every game humans have ever conceived (I think, at least) - and it has ties back in psychology. Gameplay reward loops are intrinsically tied to the Dopamine-Seeking Reward Loop (also known as the Compulsion Loop). In brief, the brain wants to encourage you to do things that are novel, fun, entertaining, etc. So, it'll prompt you to seek those behaviors and "reward" you for doing so. This is the core reason we engage with all kinds of entertainment, and without care to what the loop is rewarding you can unwittingly (or wittingly) create negative impacts in the player.

Core Gameplay Loops

It's important to understand, both when designing and playing games, that having a core gameplay loop - that is, the loop that forms the primary basis for the game in question. Without a core loop, games often feel disjointed and disconnected. Encountering published video games without a core loop is a bit more rare than TTRPGs - usually this is because if you don't figure out the gameplay loop you're probably going to run out of money before you can actually release the game.

For TTRPGs, Kickstarted or self-published games can get to release without a core gameplay loop embedded, and the free-form nature of tabletop gaming lends itself a bit more to papering over the problems of a missing or loose core loop - but even still, these are fairly uncommon. I think this it least partly because the core loops TTRPGs are reasonably well-known and generally fall into similar categories as one another.

TTRPG Gameplay Loops

There are a couple of major "themes" of gameplay loops embedded in TTRPGs. Probably the most prominent, in terms of cultural awareness is the combat loop I described above - Characters in Dungeons and Dragons (especially those from the 3rd and 4th editions) primarily advance through combat experience. They use that experience to gain levels, and get more abilities to further surmount harder combat challenges.

In some editions, this is where the player incentives stop - the core (and almost only) gameplay loop is that aforementioned XP loop. Over the years, however, there have been various attempts at other XP systems - sometimes for social encounters, sometimes for avoiding combat, and the like. These are, in my opinion, attempts at designing around the main incentive that combat-based XP systems encourage - namely "kill everything that moves".

As an example of alternative systems: an OSR game that's managed to hold my attention, Shadowdark, has a couple of different gameplay loops. The primary loop is "go into the dungeon, and gather treasure, and then use the proceeds from that treasure for a night on the town". It's similar to other treasure-for-xp systems that you can find in the B/X era D&D variants (and by extension other OSR-adjacent games that take design cues from B/X). Notably, however, Shadowdark does not reward XP for combat and it has some other XP systems - for reasons we'll discuss a little later.

Solving Problems with Violence, the Combat XP Way

So, turns out that when you design a core gameplay loop around killing "monsters", your primary player incentive is going to be to kill those monsters. In turn, that tempts you to treat every encounter with non-human (and frequently human) groups as a combat encounter which is an opportunity to then gather more xp to do more combat.

If you examine many D&D modules since 3rd edition, you'll notice this as part of the adventure design. Usually, "encounters" are going to result in a fight. You may have an out in the form of "If the party bypasses / convinces / avoids combat award XP as if they had defeated them in combat" - but the core assumption of "this will be a fight unless otherwise noted" is present deep in the game.

Even further, D&D editions after 3.0 (up to and including 5) also have the concept of a "combat day" built into the adventure design. An average party should have the ability to do {n} number of combat encounters in a given day, and after that - things will become more difficult for them, if not impossible. Character death is generally pretty rare if the "combat day" is well designed / adhered to, and once it's past that you're getting into the risk of characters dropping, or an overall wipe.

Sly Flourish has a great blog post on the subject, but to summarize the points therein - that number represents an upper threshold, not necessarily a "you do this"... but it does incentivize cramming in more encounters to create a sense of "yes, you're being taxed and this is challenging".

Now, earlier editions of D&D also included treasure-for-xp, giving you an alternative to combat to level; however it's my understanding that the amount of xp you would need to gain a level was balanced so that you needed to do both if you wanted to gain levels at a "reasonable pace" (of course, house rules and home game pacing is highly variable based on group and GM preference).

Treasure as XP, the Gentleperson Thief

So let's get back to Shadowdark and talk a little bit about its XP mechanic. The core way you gain XP in Shadowdark is by recovering treasure from lost places and taking them back to safety.

At some level this is a "It belongs in a museum" kind of mechanism - you go into the dungeon, you return with treasure, you spend the treasure, you repeat. But here are a couple of things I think it does uniquely well:

• Carousing / downtime activity often gives you XP. The more money you spend on the night out the more (generally) XP you'll receive
• You get XP for securing intangibles like promises from a lord, or pacts with devils.
• Clever thinking - this is the "oh my gods that was awesome" XP mechanic you find in a lot of story systems

All of those reinforce what I think the core loop of the game is: Head out to dangerous location, find "whatever isn't nailed down", return it to town, party, repeat. That is of course not the only way you can use the system, but I feel a lot of the XP mechanic drives that forth - go to the deep places and find adventure.

This kind of an XP system is particularly well suited to the kind of gameplay you might encounter in a hex crawl, or an open table, where you need to gear the players to a common goal without assuming character motivation. It's also particularly well designed to de-emphasize combat, you don't get XP from fighting at all, but clever action is rewarded - and GMs, avoiding combat via innovative thinking is absolutely XP worthy.

It's worth noting that Shadowdark has a series of "Modes of Play" in the core rules that you can mix and match - one of those rules is "Hunter Mode" which allows you to gain XP for killing monsters, which would bring it back in line with a more combat-incentivized game like earlier D&D variants.

Encouraging Collaborative Storytelling - The Playbook Model

It's no secret that story games are my favorite kind of games to play, and the ones I tend to gravitate towards for gameplay that I enjoy. (Of course, I also enjoy other games, but this is my "bread and butter"). Of those, I think Powered by the Apocalypse games (starting with Apocalypse World) provide the best way to illustrate the point.

PbtA games are varied in the ways they reward XP, but in Apocalypse World (the progenitor of this genre of game), you gain XP in a couple of different ways:

• Any time you roll a highlighted stat
• Any time your relationship with another player maxes out, either positively or negatively
• Certain moves mark XP.

There are a couple of different things codified directly into the XP mechanism: Encouraging you to roll a particular stat, and to change which stats are highlighted frequently. It encourages you to forge bonds of friendship, love, antagonism, and anger with the other characters. Finally, there are several moves that give you experience - a key one is when you try to seduce or manipulate someone (NPCs included), one of the results is marking XP.

The entire game design follows from “Narrativism: Story Now” by Ron Edwards. - Vincent Baker, Apocalypse World 2nd Edition p. 290

One of the core design elements of Apocalypse World boils down to the idea that you can incentivize narrative play via mechanics - and a lot of the mechanics in Apocalypse World are designed with "fiction first" play in mind. It's codified in the rules as the "Make your move but never speak its name" principle (among others).

The way this works out in the core gameplay loop is essentially the following:

• Set the scene, using previous context to guide.
• Ask "What do you do?" to the players and use the answer - triggering moves when the narrative has activated a move
• Roll to find out what happens - use the result to further the narrative.

This is further enhanced by the XP loop - you gain XP by interacting with and advancing the ongoing narrative. However, in Apocalypse World, this is a bit weaker of a loop / correlation than you find in its derivatives, as I'll demonstrate shortly.

Evolving PbtA Derivatives - Tweaking Mechanical Incentives

There are a couple of things that PbtA variants (and those games that take inspiration from Apocalypse World) have done to advance one of the core design goals of the game, while retaining the core elements of that narrativist loop.

First though, there's one thing that folks have pointed out to me that I think is very true - basically all games in the "strongly based on PbtA principles" category (a loose category I just made up on the spot) tend to use the same basic moves, just reskinned. I'll probably talk about this in a future post, but for now - it's definitely a thing and I think it's quite grounded in "we stumbled upon a really great core design element".

That aside, there has been a lot of advancement in the various XP incentives in other games. One of the best ones, I think, is "On a miss, mark experience". I don't know exactly which derivative added it, but it's definitely present in Dungeon World and a lot of the others. Blades in the Dark and derivatives replace this with "Gain XP when making a desperate roll" but the principle is similar.

In the former system, it encourages you to not be afraid of rolling the dice - and encourages you to embrace bad dice rolls. You'll gain XP if your dice betray you, at least, and the narrative will continue to spiral downward for your character. In the latter, it encourages you to take more risks - gaining XP through pushing your character and increasing the odds of failure.

And that's key. Failure is often a mechanism to drive the story forward in these games. The story itself is codified into the core gameplay loop, and really - I think these kinds of games are a lot more geared towards groups who like to improv stories together more than any other element of gameplay. The XP system is designed to directly reward that kind of play.

Conclusion

Well, here we are again, at the end of another semi-lenghty post about game design theory just falling out of my brain. I hope this was useful to some of you as you think about how a small part of system design can encourage player behavior.

I'm not sure what's going to come up next time in the Musings category, I've got a couple of things in the hopper kicking around and being refined. If you've got any particular request leave a comment (which requires signing up to prevent spam) or drop me a line at the contact form!