XEP-xxxx: Tic-tac-toe

This document defines how to play a Tic-tac-toe game over XMPP
Torsten Grote
© 1999 – 2020 XMPP Standards Foundation. SEE LEGAL NOTICES.


WARNING: This document has not yet been accepted for consideration or approved in any official manner by the XMPP Standards Foundation, and this document is not yet an XMPP Extension Protocol (XEP). If this document is accepted as a XEP by the XMPP Council, it will be published at <http://xmpp.org/extensions/> and announced on the <standards@xmpp.org> mailing list.
Standards Track
0.0.1 (2009-03-14)
Document Lifecycle
  1. Experimental
  2. Proposed
  3. Draft
  4. Final

1. Introduction

It is quite common to play games over IM networks. Since Tic-tac-toe is a well known game, XMPP needs a protocol to support it.

2. Requirements

This protocol should provide all means to play a regular game of Tic-tac-toe over XMPP.

Tic-tac-toe is also one of the simplest games and played "just for fun". Therefore no validation support is needed. The typical duration is below one minute and the matches are not of great interest for non-players. Therefore spectators do not have to be supported as well. That is why this document only describes the protocol to play a Tic-tac-toe as a One-to-One match without support for game saving and resuming.

3. Discovering Support

An entity implementing this protocol MUST also support Instant Gaming [1] and answer to disco requests accordingly including both the Instant Gaming and the game <feature/> elements in the response.

Example 1. Juliet Informs Romeo That She is Capable of Playing Tic-tac-toe
<iq type='result'
  <query xmlns='http://jabber.org/protocol/disco#info'>
    <feature var='http://jabber.org/protocol/games'/>
    <feature var='http://jabber.org/protocol/games/tictactoe'/>

4. Invitation

When inviting to a game of Tic-tac-toe, an entity SHOULD use Data Forms (XEP-0004) [2] to specify game options in the REQUIRED <game/> element. Possible options are "role" (of the inviting player), "rows" (height), "cols" (width) and "strike" (number of marks in a row needed to win). If these options are missing, all but role default to '3' and role defaults to 'x'. An implementation MUST be able to handle the default values. Everything beyond that is OPTIONAL.

Example 2. Romeo Invites Juliet
  <invite xmlns='http://jabber.org/protocol/games'
      Hello Juliet,
      would you like to play a little game?
    <game var='http://jabber.org/protocol/games/tictactoe'>
      <x xmlns='jabber:x:data' type='submit'>
        <field type='list-single' var='role'>
        <field type='text-single' var='rows'>
        <field type='text-single' var='cols'>
        <field type='text-single' var='strike'>

When sending an invitation of type "renew", the role option MUST be changed to the opposite of the role the inviting player had in the previous match with that match ID. So both players essentially switch their roles. All other options MUST stay the same.

5. Game Flow

During the game, players change in turn, each of them sending one move at a time. The player with the role 'x' makes the first move. A game move is represented as a <message/> stanza addressed to the full JID of the other player. It MUST have a <thread/> child element which specifies the match ID. Furthermore, the <message/> stanza contains a <turn/> element which in turn contains exactly one <move/> element qualified by 'http://jabber.org/protocol/games/tictactoe'. It MUST possess these attributes:

Table 1: <move/> attributes
Name Type Description
'id' REQUIRED The number of the move. First move is 1.
'row' REQUIRED The horizontal position of the mark.
'col' REQUIRED The vertical position of the mark.
Example 3. Part of the Match Between Romeo and Juliet
  <turn xmlns='http://jabber.org/protocol/games'>
    <move xmlns='http://jabber.org/protocol/games/tictactoe'

  <turn xmlns='http://jabber.org/protocol/games'>
    <move xmlns='http://jabber.org/protocol/games/tictactoe'

6. Game Termination

Notifying the players whether they have won or lost is in responsibility of the game client. The game is considered terminated when the board is full, i.e. nine moves have been made. For further termination conditions see the appropriate section of Instant Gaming [1].

7. Security Considerations

The author is not aware of any security issues introduced by this protocol extension.

8. IANA Considerations

This document requires no interaction with the Internet Assigned Numbers Authority (IANA) [3].

9. XMPP Registrar Considerations

The XMPP Registrar [4] shall include 'http://jabber.org/protocol/games/tictactoe' in its registry of protocols.

10. XML Schema

<?xml version='1.0' encoding='UTF-8'?>


<xs:element name='move'>
    <xs:attribute name='col' type='positiveInteger'/>
    <xs:attribute name='row' type='positiveInteger'/>
    <xs:attribute name='id' type='positiveInteger'/>



Appendix A: Document Information

XMPP Standards Foundation
Standards Track
Last Updated
Approving Body
XMPP Council
XMPP Core, XEP-xxxx
Superseded By
Short Name
Not yet assigned

This document in other formats: XML  PDF

Appendix B: Author Information

Torsten Grote


This XMPP Extension Protocol is copyright © 1999 – 2020 by the XMPP Standards Foundation (XSF).


Permission is hereby granted, free of charge, to any person obtaining a copy of this specification (the "Specification"), to make use of the Specification without restriction, including without limitation the rights to implement the Specification in a software program, deploy the Specification in a network service, and copy, modify, merge, publish, translate, distribute, sublicense, or sell copies of the Specification, and to permit persons to whom the Specification is furnished to do so, subject to the condition that the foregoing copyright notice and this permission notice shall be included in all copies or substantial portions of the Specification. Unless separate permission is granted, modified works that are redistributed shall not contain misleading information regarding the authors, title, number, or publisher of the Specification, and shall not claim endorsement of the modified works by the authors, any organization or project to which the authors belong, or the XMPP Standards Foundation.

Disclaimer of Warranty

## NOTE WELL: This Specification is provided on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, express or implied, including, without limitation, any warranties or conditions of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A PARTICULAR PURPOSE. ##

Limitation of Liability

In no event and under no legal theory, whether in tort (including negligence), contract, or otherwise, unless required by applicable law (such as deliberate and grossly negligent acts) or agreed to in writing, shall the XMPP Standards Foundation or any author of this Specification be liable for damages, including any direct, indirect, special, incidental, or consequential damages of any character arising from, out of, or in connection with the Specification or the implementation, deployment, or other use of the Specification (including but not limited to damages for loss of goodwill, work stoppage, computer failure or malfunction, or any and all other commercial damages or losses), even if the XMPP Standards Foundation or such author has been advised of the possibility of such damages.

IPR Conformance

This XMPP Extension Protocol has been contributed in full conformance with the XSF's Intellectual Property Rights Policy (a copy of which can be found at <https://xmpp.org/about/xsf/ipr-policy> or obtained by writing to XMPP Standards Foundation, P.O. Box 787, Parker, CO 80134 USA).

Visual Presentation

The HTML representation (you are looking at) is maintained by the XSF. It is based on the YAML CSS Framework, which is licensed under the terms of the CC-BY-SA 2.0 license.

Appendix D: Relation to XMPP

The Extensible Messaging and Presence Protocol (XMPP) is defined in the XMPP Core (RFC 6120) and XMPP IM (RFC 6121) specifications contributed by the XMPP Standards Foundation to the Internet Standards Process, which is managed by the Internet Engineering Task Force in accordance with RFC 2026. Any protocol defined in this document has been developed outside the Internet Standards Process and is to be understood as an extension to XMPP rather than as an evolution, development, or modification of XMPP itself.

Appendix E: Discussion Venue

The primary venue for discussion of XMPP Extension Protocols is the <standards@xmpp.org> discussion list.

Discussion on other xmpp.org discussion lists might also be appropriate; see <http://xmpp.org/about/discuss.shtml> for a complete list.

Errata can be sent to <editor@xmpp.org>.

Appendix F: Requirements Conformance

The following requirements keywords as used in this document are to be interpreted as described in RFC 2119: "MUST", "SHALL", "REQUIRED"; "MUST NOT", "SHALL NOT"; "SHOULD", "RECOMMENDED"; "SHOULD NOT", "NOT RECOMMENDED"; "MAY", "OPTIONAL".

Appendix G: Notes

1. XEP-xxxx: Instant Gaming <http://pidgin-games.sourceforge.net/xep/instant-gaming.html>.

2. XEP-0004: Data Forms <https://xmpp.org/extensions/xep-0004.html>.

3. The Internet Assigned Numbers Authority (IANA) is the central coordinator for the assignment of unique parameter values for Internet protocols, such as port numbers and URI schemes. For further information, see <http://www.iana.org/>.

4. The XMPP Registrar maintains a list of reserved protocol namespaces as well as registries of parameters used in the context of XMPP extension protocols approved by the XMPP Standards Foundation. For further information, see <https://xmpp.org/registrar/>.

Appendix H: Revision History

Note: Older versions of this specification might be available at http://xmpp.org/extensions/attic/

  1. Version 0.0.1 (2009-03-14)

    First Draft.