Whenever the wearer of this ring desires, he or she is able to magically blend in with the surroundings.

This enables 90% invisibility in foliage, against walls, and so forth. 

If the wearer is associating with creatures with Intelligence of 4 or greater at a distance of 6" or less, the dweomer of the ring enables the wearer to seem to be one of those creatures, but each turn of such association carries a 5% cumulative chance that the creatures will detect the ring wearer for what he or she actually is. 

Thus, such an association can never persist for more than 20 turns without the wearer being detected, because at the end of that time the chance of detection has risen to 100%. 

In addition, creatures with 16 or greater Intelligence use their Intelligence score as an addition to the base chance of detection - i.e., 21% at the end of turn 1, 26% at the end of turn 2, and so forth, if a creature of 16 Intelligence is involved. Creatures with 3 or lower Intelligence will instinctively and automatically detect the wearer if they come within a 1" radius of him or her.