World 5

Systems

Economies, randomness, feedback loops and balance: the machinery beneath the surface.

Most of what makes a game replayable is arithmetic nobody sees: how fast money appears, how often luck runs bad, whether one choice quietly beats all the others. Small numbers here have huge consequences that no one predicts by reading the design document, and players find every one of them within a week. These words let you say which machine is broken and what to do about it, instead of saying the economy feels off or the game feels unfair.

ResourceAnything a player has a limited amount of and can spend or use up to get something else: gold, ammunition, health, time on the clock, a turn. If it is scarce and you can choose how to spend it, it is a resource.
Positive feedback loopA loop where doing well makes you better at doing well: winning gets you the thing that helps you win. Positive here means it amplifies, not that it is good.
Negative feedback loopA loop that pulls the leader back or lifts whoever is behind, so that the contest stays close. Negative here means it dampens, not that it is bad.
EmergenceBehaviour that nobody wrote, arising from a few simple rules interacting. The game's designers can be as surprised by it as anyone.
Systemic designBuilding a game from general rules that apply to everything, rather than special cases for each puzzle. If fire burns grass, it burns all grass, whoever lit it, and any solution those rules allow is a real solution.
Faucets and sinksA faucet creates a resource out of nothing, as when monsters drop gold. A sink destroys it for good, as when you pay an NPC for repairs. Money passing between players is neither: it just moves.
InflationPrices rise because there is more money around, not because anything got better. In a game with no sinks it is almost guaranteed, since players keep producing money and rarely destroy it.
RNGThe part of a game that makes up random numbers. It is really a formula that produces a long list that only looks random, starting from one number called a seed, so the same seed always gives the same list.
Input and output randomnessInput randomness happens before you choose, and you plan around it: the cards you were dealt, a random map. Output randomness happens after you choose and can overturn it: you aim, and then a die says whether you hit.
Pseudo-random distributionRandomness that bends towards its average: each miss raises the chance of the next hit, and each hit resets it. The long-run rate stays the same and the streaks mostly go away. A shuffle bag does a similar job by dealing out a fixed set.
Pity timerA guarantee that after so many failed rolls, the next one pays out. It cuts off the worst luck anyone can have, without changing the rate for everyone else very much.
Weighted loot tableA list of what can drop, each with a weight. Add up the weights, roll a number in that range, and see whose slice it lands in. A weight of 1 in a table totalling 100 is a 1% chance.
Opportunity costWhat a choice really costs you is the best other thing you could have done with it. The gold you spent on a farm is a soldier you don't have when the raid comes.
Dominant strategyA choice that is at least as good as every alternative, whatever the opponent does. Once people find it, the rest of your options might as well not exist.
Intransitive balanceA loop of counters where A beats B, B beats C and C beats A, so there is no best choice, only a best choice against what the other side is doing.
Power curveHow a player's strength rises over time, usually drawn against the same for enemies. Linear growth adds the same amount each step. Exponential growth multiplies by the same amount each step, so it starts slowly and then leaves everything behind.
Soft cap and hard capA hard cap is a limit that can't be passed. A soft cap is a point past which each extra bit does less, so more is still allowed, and hardly worth buying.
Buff and nerfA buff makes something stronger and a nerf makes it weaker. Nerf is named after the foam toys: a nerfed weapon is one that now hits like foam.
The metaWhat most people are playing at the moment, and the choices that makes best in reply. It is the game above the game: you don't only pick what's strong, you pick what beats what everyone else is picking.
Tech treeA map of upgrades where each one requires those before it, so that buying one opens the next. You can't afford all of it, so your path through it is your strategy, and it is visible to you and often to your rivals.
Build diversityHow many different ways of setting up your character or army are actually good enough to use. A game may offer thousands, and only the ones close to the best count.
Min-maxingMaking one thing as high as you can by making another as low as you dare. Which build is best follows from the formula, so changing the formula changes how people play.
Action economyIn a turn-based fight, how many things each side gets to do. A party of four with four actions usually beats one monster with four times the health and damage, because that single monster wastes damage and can be stunned out of its whole turn.
DPS and time to killDPS is average damage over time. Time to kill is how long it really takes to bring something down. They differ because damage comes in lumps: it takes a whole extra shot to deal the last point of damage.
Perfect imbalanceKeeping a competitive game a little off balance on purpose, and changing which way it leans every so often. Players never settle on one solved answer, so there is always something new to work out. Extra Credits popularised the phrase in 2012.
Nash equilibriumA set of strategies where nobody can do better by changing theirs alone. Often it means mixing your choices in exact proportions, so that the other side can't exploit you whatever they do.
Prisoner's dilemmaTwo players each pick cooperate or betray. Betraying is always better for you whatever the other does, yet both end up worse off than if both had cooperated. Play it many times and things change, because betrayal can then be punished.