Moon Logic
Absurd adventure puzzles
Moon logic describes adventure game puzzles whose solutions make sense only to their designers, requiring leaps of reasoning that frustrated players while becoming the genre's defining criticism.
Use the monkey on the water pump. Obviously. Moon logic puzzles became adventure gaming’s greatest liability—solutions that made designers laugh but made players reach for walkthroughs. The term captured the genre’s worst tendency: puzzles requiring knowledge players couldn’t reasonably possess or connections they couldn’t reasonably make.
Fast facts
- Definition: Illogical puzzle solutions.
- Origin: Player frustration term.
- Impact: Genre criticism.
- Result: Walkthrough dependence.
The rule it breaks was written down in 1990
⚠ This is not only a retrospective complaint. Ron Gilbert set out the test in Why Adventure Games Suck, abstracted in Computer Gaming World in April 1990 — rule 9 of “Gilbert’s Rules of Thumb”, Avoid arbitrary puzzles:
While puzzles do not have to be obvious, they should make enough sense that the player’s first thought upon solving it is, “Of course, why didn’t I think of that sooner!” If the solution can only be reached by trial and error (or plain luck), it’s a bad puzzle.
That is a usable criterion, and it is stricter than “the solution was weird”: the test is the player’s reaction after solving it. A good puzzle feels retroactively inevitable.
Gilbert’s reasoning is also stronger than player irritation. His thesis “relates to the necessity of ‘suspension of disbelief’”, which “disappears every time the player has to restore a saved game or ends up pounding his or her head on the desk in frustration”. A moon-logic puzzle is a failure of fiction, not just of fairness.
Rule 10, Reward the player’s intent, names two mechanical versions of the same sin: “It should not be a matter of having a character on just the right pixel in a graphics game or guessing just the right word in a parser-driven game.” His summary: “If you give the player the benefit of the doubt, the game will be right more than wrong.”
Characteristics
| Trait | Example |
|---|---|
| Arbitrary combinations | Random item use |
| Hidden requirements | Obscure prerequisites |
| Designer-only logic | Internal jokes |
| Cultural assumptions | Regional knowledge |
Infamous examples
| Game | Puzzle | Issue |
|---|---|---|
| Gabriel Knight 3 | Cat hair moustache | Absurd chain |
| Discworld | Inventory combinations | Everything on everything |
| Various | Pixel hunting | Tiny clickable areas |
Causes
| Factor | Result |
|---|---|
| Development isolation | No fresh eyes |
| Hint line revenue | Obscurity profitable |
| Length padding | Artificial difficulty |
| Comedy attempts | Jokes over logic |
Player responses
| Coping method | Frequency |
|---|---|
| Walkthroughs | Routine, and often necessary |
| Hint books | Purchase required |
| Try everything | Exhaustive testing |
| Community help | Forums, BBSes |
Designer defences
| Argument | Counter |
|---|---|
| “It’s logical” | Only to you |
| “Reward exploration” | Frustration isn’t reward |
| “Adventure tradition” | Tradition can be wrong |
Genre impact
| Effect | Consequence |
|---|---|
| Walkthrough dependence | External help expected |
| Genre decline | Players gave up |
| Design evolution | Fairer puzzles later |
Modern solutions
| Approach | Implementation |
|---|---|
| Hint systems | In-game assistance |
| Logical design | Fair puzzles |
| Playtesting | Fresh perspectives |