Making difficulty curves in games

http://www.davetech.co.uk/difficultycurves

Tricks for Keeping Everyone on the Right Part of the Curve:

DO:

• Put in optional collectables
• Provide tricky alternate routes that skips easy parts
• Have areas that give you a better high score
• Achievements that reward people playing with a disadvantage
• Dynamically adjust the difficulty depending on how well the player is doing. <- This is actually magic sauce and could be the topic of a whole talk.
• Have multiple endings.
• Allow people to grind for exp or practice if they feel they are not capable of an area.
• Have multiple paths so if the player gets stuck they can do another task until they have the skills needed to go down the main path.
• Make it obvious what equipment players need to be using for this puzzle (by giving it to them right away, giving them ammo for the needed weapon, colour coding things, removing previous equipment that is not needed for this puzzle)
• Give people multiple ways to learn something (text, voice over, button prompt, particles showing where they need to go, environmental graphics, lighting, help popups, visual cues)
• Give subtle graphical hints (In Mario there will be a little flower or coin where you need to start a jump)
• Just visually show them (often in games before being given a new weapon you will see an enemy use it on the other side of a window, or you will see the kind of damage it has done to other NPCs in the room)

DON’T:

• Don’t make the game easier for people who are doing better (for example putting skill points in an area only expert players can get to)
• Don’t punish someone for doing bad and make future attempts harder
• Don’t allow someone to skip an area if they haven’t learnt the skill they need
• Don’t hide things as the main mechanic of a puzzle
• Don’t put a long cutscene / intro that can’t be skipped in an area with lots of retry attempts.
• Don’t display things the player doesn’t need to know right now (don’t overwhelm them with descriptions of skills that are not on their path)

Don’t just make the game harder; Show the player they are getting better.

Something that works well is to show people how far they have come, you see games having nods back to previous puzzles, often they add something fresh or obfuscate it but it’s nice for the player to see how much better they are now. Plenty of times I’ve been playing a game and I didn’t get a simple puzzle because I’m expecting something harder, but it turns out the answer is a twist on something I learnt earlier in the game.

On this same vein I get really excited when I find out a game had a really hard puzzle on the first level hidden in plain sight, but it isn’t until later levels that you learn how the puzzle works. It’s like a locked door where the key is knowledge. (I wanted to give some examples of this but then I thought just naming the game is a massive spoiler)

This does allow us to talk about one fantastic trick that really ties into the whole idea of keeping people on the correct part of the graph. Hiding a shortcut with pure knowledge. Portal 2 has a great example of this, one of the levels has the start and end of the level right near each other, and with some clever placement of portals it is possible to skip the whole level, however it uses techniques you don’t learn until later in the game, the developers knew about this but said if someone is able to trick their way straight to the end then the level has nothing to teach them.