This spell influences the actions of the target by suggesting a course of action desirable to the spellcaster. The creature to be influenced must, of course, be able to understand the caster's Suggestion - it must be spoken in a language they understand.
The suggestion must be worded in such a manner as to make the action sound reasonable; asking the creature to stab itself, throw itself onto a spear, immolate itself, or do some other obviously harmful act automatically negates the effect of the spell.
However, a suggestion that a pool of acid was actually pure water and that a quick dip would be refreshing is another matter. Urging a Draken to stop attacking the party so that the Draken and party could jointly loot a rich treasure elsewhere is likewise a reasonable use of the spell's power.
The course of action of a Suggestion can continue in effect for a considerable duration, such as in the case of the Draken mentioned above.
Conditions which will trigger a special action can also be specified; if the condition is not met while the spell is being maintained, then the action will not be performed.
If the target successfully rolls its POW check, the spell has no effect.
Note that a very reasonable suggestion causes the POW check to be made with Disadvantage at the discretion of the Storyteller.
The Soulless are not subject to suggestion.