The EBNF describes all the messages that can be sent from the server to a client. Rules are written in ALLCAPS, while literals are enclosed in quotation marks.

S: "begin:",INT,SERVERMES,"end:",INT
SERVERMES: UPDATE|DELETE|MAP|MESSAGE|ANSWER|RESULT|CHALLENGE|PLAYER|YOURID|TIME|ONLINE|ENTITIES|PLAYERS|SERVER
SERVER: "begin:server","ver:",INT,"end:server"
RESULT: "begin:result","round:",INT,"running:",BOOLEAN,"delay:",INT,"begin:opponents",OPPONENT,OPPONENT","end:opponents","end:result"
OPPONENT: "begin:opponent","id:"INT,"decision:",DECISION,"points:",INT,"total:",INT,"end:opponent"
CHALLENGE: "begin:challenge","id:",INT,"type:",("DRAGON"|"STAGHUNT"|"SKIRMISH"),"accepted:",BOOLEAN,"end:challenge"
DRAGON: "begin:dragon", "id:",INT,"type:Dragon","busy:"BOOLEAN,"desc:"STRING,"x:",INT,"y:",INT,"end:dragon"
PLAYER: "begin:player","id:",INT,"type:Player","busy:"BOOLEAN,"desc:"STRING,"x:",INT,"y:",INT,"points:",INT"end:player"
PLAYERS: "begin:players",{PLAYER},"end:players"
ENTITIES: "begin:ents",{(PLAYER|DRAGON)},"end:ents"
MAPCELL: "begin:cell","row:",INT,"col:",INT,"begin:props",{PROPERTY},"end:props","end:cell"
MAP: "begin:map","width:"INT,"height:",INT,"begin:cells",{MAPCELL},"end:cells","end:map"
MESSAGE: "begin:mes","srcid:",INT,"src:",STRING,"txt:",STRING,"end:mes"
UPDATE: "begin:upd",(DRAGON|PLAYER|MAPCELL),"end:upd"
DELETE: "begin:del",(DRAGON|PLAYER),"end:del"
ANSWER: OKAY|DENY|UNKNOWN|INVALID
OKAY: "ans:ok"
DENY: "ans:no"
UNKNOWN: "ans:unknown:",STRING
INVALID: "ans:invalid"
YOURID: "begin:yourid",INT,"end:yourid"
TIME: "begin:time",LONG,"end:time"
ONLINE: "begin:online",INT,"end:online"
DECISION: DRAGONFIGHT|STAGHUNT|SKIRMISH
DRAGONFIGHT: "FIGHT"|"REST"
STAGHUNT: "STAG"|"BUNNY"
SKIRMISH: "SWORD"|"ALCHEMY"|"MAGIC"
PROPERTY: "WALKABLE"|"WALL"|"FOREST"|"WATER"|"HUNTABLE"