After the spacial movement rules of a game have been established (walking, crouching, jumping, climbing), players will expect to be able to apply these rules, when the world geometry indicates that possibility.
Invisible walls limit such established rules and discovering to be in your way is a frustrating experience.
Mountains and water often serve as “natural” walls but sometimes invisible walls are inevitable. Be it due to restrictions on time, resource or innovation. There are however three easy ways to reduce the frustration effect:
1. Make energy or magic barriers part of the game fiction
Image: creation of the big energy barrier in Gothic I. If you come too close to it in-game, you will be pushed and lose health.
Even better when these invisible barriers are kind of visible or are even interactive.
2. Place signs
Yes, it is that easy. Whether serious or funny, signs do help.
3. Be honest. Talk to the player about it.
It is a popular relationship advice and even helps against human spammers. Simly mentioning – using already available “hint” mechanics or in-game characters – that in some places, the laws of logical movement do not apply, will make invisible walls more acceptable.
Do you have any ideas/examples of acceptable use of invisible walls? Comment below!