Chapter III. Attempt and Participation.
Art. 20
Any person who has resolved to commit an act punishable under this Act and has clearly demonstrated this resolve by an act aimed at commission or designed as such is, if the offence has not been completed, guilty of an attempted offence.
For an attempted offence, a lower penalty may be ordered than for a completed offence. This shall, in particular, be done in cases where the attempt indicates that the offender is less dangerous and his/her resolution not as firm as that of persons who complete such offences.
If the attempt could not have led to a completion of the offence because of the interests threatened or the act itself, a penalty may be cancelled.
Art. 21
Penalty shall not be ordered on account of an attempted offence if the offender of his/her own accord abandons his/her intention to commit the offence before it has been completed, provided the commission of the offence has not been thwarted or an impediment or other fortuitous occurrence have prevented the offender's design from being achieved and the offender has, in addition, if he/she has by his/her act caused or expected a danger of completion, prevented its completion or taken measures that would have prevented it, if completion had not been thwarted for other reasons without his/her knowledge or proved impossible.
Art. 22
Any person who in word or deed provides aid in the commission of a punishable act defined in this Act, or takes, by persuasion, exhortation or otherwise a part in committing such act, shall be punished as provided for in the provision applying to the offence.
If the role of a participant in the commission of an offence is of minor nature, or if it involves the strengthening of another person's resolve already formed, if the offence has not been completed, or if the planned participation has failed, penalty may be ordered which is lower than that prescribed in the applicable provision.
In a situation defined in para. 2 and also when a person has become a participant in the commission of an offence by inadvertence penalty may be cancelled if the act comes under a penal provision providing for a penalty not heavier than [up to 1 year’;s imprisonment.]
If an offence has been completed, a person who aids the offender himself/herself or any other person in maintaining an unlawful situation created by the offence, or enjoys any profits created thereby shall be punished in accordance with the provisions of this Article subject to any other statutory provisions which may apply to his/her act.
Art. 23
An accessory shall not be subjected to penalties if he or she does in the manner stated in Art. 21 avert the offence or takes measures that would have prevented the offence if its commission had not been thwarted for other reasons without the accessory's knowledge, failed or proved impossible.
Individual criminal responsibility
Abetting
Aiding
Assisting
Inducing
Ordering
Providing means
Soliciting
Incitement - other crimes
Joint commission
EDIT.