I have not found any expression for collisions in Gdevelop. I miss the expression “other” from Game Make Studio. It’s very useful when two instances of the same object collide, so you can check things by using “other” to distinguish between the two instances. Any alternative to distinguish between the instance you check and the other instance if they are of the same object? taking into account that they are checked reciprocally and there are many instances, for example eight of the same object, which can collide with each other.
Collusions are technically instant at the same time, so between the same object isnt easy to differentiate currently.
The collision condition is the only main collision condition.
However, the “pick object” conditions can fill some of these needs. The main one I usually use is pick random.
There are some discussions on the github around more pick objectsl conditions, but it is unclear if/when more will added.