Single-Player Mapping Tips

Introduction

This article sums up a list of useful hints and tips relating to single-player mapping, in no particular order. Originally available on the VERC (but with some changes), it should be sufficiently general for most mappers interested by this difficult and often overlooked aspect of mapping.

Architecture and layout

• Tell a story. Why are things like this? What is the player doing? Make it look like something has happened, and give the player something to fight towards.
• Loops are often a good idea. Let the player catch glimpses of where they are meant to be going. It can help to reduce any unpleasant linearity in your maps. Make getting straight through to those areas obviously impossible - it's no fun being taunted by the exit that's blocked off by a ledge that's just a tiny bit too high to jump.
• Reuse space. A long level doesn't have to be physically long. Much like a Loop, reusing space saves on both memory, and work time. Instead of just having a player go back, have them spend time in area they have previously visited. Whether they need to find a valve to unlock a gate, or turn on a physics puzzle to progress, reusing space can give even the smallest area in a map a lot of playtime, and help to further enhance the gameplay.
• Make the architecture appear functional. It shouldn't look like it was built solely for shooting monsters in - it's supposed to be a realistic portrayal of an actual place, whose architecture (ever so conveniently) aids or hinders the player's quest.
• If a door has to be locked, make it obvious, and if it's to be unlocked, make that obvious too. Half-Life 2 helps by the use of door hardware, where the presence of a door handle indicates that it can be opened. Lots of inaccessible doors also had Combine locking mechanism models attached to them.
• Vents can be acceptable if used sparingly. They can be good for letting the player get into a room when the door's blocked, but not for mini-adventures lasting several hours apiece. Be careful with headcrabs in vents - they're obvious and so not-scary. Their absence would probably be terrifying... Also, players probably expect the vents to be penetrated by bullets.
• Break your map up into playable areas or chapters. This helps organize the game flow and gives the player indication of progress. As part of this, it is a good idea to periodically block the player from backtracking to ensure flow is maintained, however, care should be taken not to overuse this technique, as it can become very obvious and feel artificial if overused, for further details on this see Push Gameplay .
• Always consider the architecture of your map outside of the game. This helps establish how the environment should look and sound; if you've got a particular structure, ask yourself: Why is it there? What sort of things can I expect around it? What sort of things would I not expect in real life? Work with the players own assumptions (put yourself in the player's shoes) to offer enhanced atmosphere and gameplay opportunities.
• Pace the map. If you've just forced an epic battle upon the player, give them time to recuperate. For every 15 minutes of straight-out combat, they should have about 5 minutes of rest and/or exploration. Their eyes, brain and hands will appreciate the rest, but they'll also be wary of what might happen next...
• The best maps give a subtle indication showing the player where to go. Whilst not big arrows in the sky, clever geometry, architecture, environmental details and lighting will help direct the player accordingly. Again, always remember to work with the player's own knowledge and assumptions, but be prepared for those who have remembered next to nothing.
• There should always be a way out. The player should never need to suicide or reload because they went left instead of right or down instead of up. Many maps fail this simple test over and over again. As long as the player is alive, they should have some way to advance.
• Avoid forcing flashlight use for long periods. Dark sections that need the flashlight can work, especially if they bring in new gameplay elements, for instance, "Lowlife" in Episode 1. However, even Episode 1 provided alternative means of light and had lighter areas as "breaks". Pure darkness with the flashlight as the only source of light for more than a couple of minutes is likely to become very trite and not enhance the atmosphere at all.

Enemies and item placement

• Make things hard, but fair. There's no fun in fighting a single headcrab with a rocket launcher; then again, the player is unlikely to enjoy taking on the whole of the Combine with just a crowbar.
• Don't feel you have to fill the entire place with enemies. If there's a monster behind every corner, it destroys any kind of surprise. Levels that are filled with enemies around every corner are commonly called corridor shooters, where literally the level is nothing but running, and gunning. It's scarier when you have no idea what to expect (but please avoid the temptation of putting a gunship in a cupboard)
• Use crates sparingly. Place items to be collected on shelves or even the floor, as it's not much fun having to smash your way through a cubic  kilometer of crates to find a couple of bullets. If you do use crates, make sure you differentiate between breakable and unbreakable crates. They should look completely different - and be consistent!
• Multi-sided battles can be great fun. Being caught in the middle of a firefight between soldiers and aliens really adds to the atmosphere and makes gameplay much more unpredictable. Sometimes things go in your favor, other times you're in the midst of it. Sometimes you can sit back and relax until there's just a single headcrab left...
• Consider the player's arsenal of weapons when planning out battles and puzzles. Players love having exactly the right weapon for a particular job, but having the wrong weapon out to deal with the next problem - just for a moment - helps elevate the sense of tension and excitement. Keep the player on their toes.

Atmosphere and ambience

• Use env_soundscape entities - when used properly, they can multiply spooky ambience by a large factor. Also, use additional ambient sounds where appropriate. They can contribute a lot to a map's atmosphere, but don't overdo it!
• Fog can do a great amount for giving an atmosphere to a level. Using multiple colors of fog for outdoor/indoor transitions can really sell the effect even more. If a small room is on fire, a thick fog with smoke should engulf the area. Different times of the day can also carry their own fog, and using different fog levels and color can help illustrate a change in the day.

Scripting and AI

• Let enemies react to what's happening. Don't just have independent rooms full of monsters - let soldiers call for backup, retreat or appear to respond to recent events.
• Have things change in response to the player's actions. A good single-player map might have very few obvious scripted sequences, but there can still be a hell of a lot of scripting present.
• Place AI nodes and place them well. A formerly stupid alien can behave more like Einstein when the AI node network is set up correctly. There are commands for debugging AI, such as displaying interconnections between nodes. Use them.

Construction and testing methodology

• Compile early, compile often. Try playing your map before it's actually finished to prevent potentially catastrophic scaling and gameplay errors.
• Test with monsters in-place. Early on, scatter some appropriate monsters around your map. While they won't be the final enemies, they'll help you decide where things should eventually go, and can be invaluable in telling you which architecture works and which doesn't.
• Create small test maps for ideas you might have. Pouring your ideas into a smaller level made for them can save you on a lot of wasted compile time to see its effect in a much larger, harder to compile level.
• Tune your map. This can take weeks and can make or break a map. Adjust timings in all your entity outputs until things are spot on, tweak the positioning of monsters until they respond when the player is in just the right position and fix all minor bugs, glitches or oddities you find. A tenth of a second timing or ten units in a single monster's position can transform your map.
• Be stupid. Do stupid things. Play stupidly. Map stupidly. You'll spot errors, discover problems and invent new ideas.
• Be clever. Use common sense. Don't spend too much time on one tiny thing. Expect the player to do the same.

Real life Inspiration

• Look outside or walk around your neighbourhood. A lot of the time, inspiration for an area or puzzle will come from real places!

See also

• What makes a good level? - a brief introduction to an overall design attitude towards mapping.