diff --git a/README.md b/README.md
index 5b10887..5b8a827 100755
--- a/README.md
+++ b/README.md
@@ -47,20 +47,7 @@ The package can also be installed after cloning the git repository:
 git clone git@github.com:timflutre/PlantBreedGame.git
 ```
 
-2. Then, enter into the `PlantBreedGame` directory; inside, run the script `plantbreedgame_setup.Rmd` using [Rmarkdown](http://rmarkdown.rstudio.com/) to simulate the initial data set, this can be done with the command:
-
-```sh
-make data
-```
-
-> Or with R:
->  ```sh
->  R -e "rmarkdown::render('plantbreedgame_setup.Rmd')"
->  ```
-
- It also creates all the necessary files and database for the game to function, and initiate the game with two players, "test" (no password) and "admin" (password `1234`).
-
-3. Finally, open a R session, and execute the following commands:
+2. Finally, open a R session, and execute the following commands:
 
 ```
 library(shiny)
@@ -95,18 +82,12 @@ Then, create a new directory for the application (let's call it `breeding-game`
 mkdir /srv/shiny-server/breeding-game
 ```
 
-and copy inside the content of our Shiny application you just downloaded:
+and copy inside the content of the Shiny application you just downloaded:
 
 ```
 cp -r ~/PlantBreedGame-master/* /srv/shiny-server/breeding-game
 ```
 
-Generate the game data with:
-
-```sh
-R -e "rmarkdown::render('/srv/shiny-server/breeding-game/plantbreedgame_setup.Rmd')"
-```
-
 By default, the Shiny server runs as a unix user named `shiny`.
 You hence need to create a unix group, named for instance `breeding`, to which the `shiny` user can be added (the Shiny server may need to be restarted for this to be taken into account).
 
@@ -214,8 +195,7 @@ or
 git clone --depth=1 https://github.com/timflutre/PlantBreedGame.git
 ```
 
-2. modify the file `PlantBreedGame/plantbreedgame_setup.Rmd`
-3. move in the app code folder and build a new image:
+2. move in the app code folder and build a new image:
 
 ```sh
 cd PlantBreedGame
@@ -224,8 +204,23 @@ docker build -t customplantbreedgame ./
 
 You can then run this image by using the same commands as above replacing `juliendiot/plantbreedgame` by `customplantbreedgame`
 
+
 # Usage
 
+## Game Initialisation
+
+To start playing, the game need some specific data (eg. the genotypes and haplotypes of the initial population, a data-base...). This initialisation can be done through the game.
+
+The first time you run the application, most of the game menus will show a message asking you to initialise the game. To do so you need to go to the `Admin` menue, and in `Game Initialisation` tab. There you will find a button that will start the game initialisation. Once the initialisation is completed (which takes about 2 minutes), the page will automatically reload and you will be able to connect and play the game.
+
+The game initialisation will automatically create an `admin` breeder with the default password `1234`.
+
+If the game have already been initialise, it is also possible to re-initialise it to start a new "fresh game". However in such case **all the data of the game will be lost**.
+
+> NOTE: Currently the game do not let you choose the game initialisation parameters, in order to change them, you need to manually modify the file `plantbreedgame_setup.Rmd` befor proceding to the initialisation. In a near future, you will be able to set the intialisation parameters from the game.
+
+## How to play
+
 Once the application is installed and working, _please_ read the game rules (tab `How to play?`) and start by downloading the initial data set as well as example files showing how requests should be formatted (all files listed at the bottom of the tab `How to play?`).
 
 Before making any request, such as phenotyping, you need to log in (tab `Identification`).
diff --git a/src/fun/func_dbRequests.R b/src/fun/func_dbRequests.R
index a0e292f..ef55b21 100644
--- a/src/fun/func_dbRequests.R
+++ b/src/fun/func_dbRequests.R
@@ -119,3 +119,148 @@ getBreedersIndividuals <- function(breeder) {
   query <- paste0("SELECT * FROM ", tbl)
   return(db_get_request(query))
 }
+
+clean_data_root <- function(data_root = DATA_ROOT) {
+  # WARN / TODO --- IMPORTANT ! ---
+  # the initialisation script do not allow its execution if "the data" folder
+  # already exists.
+  # Therefore here we will delete this folder, however, in general,
+  # IT IS QUITE RISKY to delete folder with code. For example:
+  # - if `DATA_ROOT` have been wrongly defined
+  # - if a malicious agent placed files/folder inside DATA_ROOT
+  # - if files are currently beeing created
+  #
+  # A better approach could be instead to only create a new `DATA_ROOT` folder
+  # and save in the data-base (that should only be erase, not deleted) the current
+  # `DATA_ROOT` to use.
+  # The server administrator would then responsible to safely remove the unecessary data.
+  #
+  # Here, to mitigate the risks the application will remove the files it
+  # has created (based on their names) and the folders if they are empty.
+  #
+  # WARN / TODO --- IMPORTANT ! ---
+
+  data_truth <- file.path(data_root, "truth")
+  data_shared <- file.path(data_root, "shared")
+  data_initial_data <- file.path(data_shared, "initial_data")
+  data_db <- file.path(data_root, "breeding-game.sqlite")
+
+
+  # initial files.
+  initial_haplo_files <- sprintf( # `Coll0001_haplos.RData` to `Coll1000_haplos.RData`
+    paste0(
+      "Coll",
+      "%0", floor(log10(1000)) + 1, "i",
+      "_haplos.RData"
+    ),
+    seq(1000)
+  )
+
+  initial_files_truth <- file.path(data_truth, c(
+    "afs0.RData",
+    "allBV.RData",
+    "coll.RData",
+    "g0.RData",
+    "p0.RData",
+    initial_haplo_files
+  ))
+  initial_files_shared <- file.path(data_shared, c(
+    file.path("initial_data", c(
+      "controls.txt",
+      "example_request_plant_material.txt",
+      "Result_phenos_controls.txt.gz",
+      "snp_coords_hd.txt.gz",
+      "example_request_data.txt",
+      "Result_genos_subset-initialColl-hd.txt.gz",
+      "Result_phenos_initialColl.txt.gz",
+      "snp_coords_ld.txt.gz"
+    )),
+    "Evaluation.txt"
+  ))
+
+  # breeder related files
+  breeders_files <- unlist(lapply(getBreederList(data_db), function(breeder) {
+    # truth
+    all_breeder_inds <- getBreedersIndividuals(breeder)$child
+    haplo_files <- c(
+      initial_haplo_files,
+      paste0(all_breeder_inds, "_haplos.RData")
+    )
+    truth_files <- file.path(data_truth, breeder, haplo_files)
+
+    # shared
+    shared_files <- file.path(data_shared, breeder, c(
+      list.files(
+        file.path(data_shared, breeder),
+        pattern = "^IndList_\\d{4}-\\d{2}-\\d{2}(_\\d+)*\\.txt$"
+      ),
+      list.files(
+        file.path(data_shared, breeder),
+        pattern = "^Request-geno_(.*)\\.txt$"
+      ),
+      list.files(
+        file.path(data_shared, breeder),
+        pattern = "^Request-pheno_(.*)\\.txt$"
+      ),
+      list.files(
+        file.path(data_shared, breeder),
+        pattern = "^Request-pltMat_(.*)\\.txt$"
+      ),
+      list.files(
+        file.path(data_shared, breeder),
+        pattern = "^Result_genos-((hd)|(ld)|(single-snps))_(.*)_\\d{4}-\\d{2}-\\d{2}(_\\d)*\\.txt\\.gz$"
+      ),
+      list.files(
+        file.path(data_shared, breeder),
+        pattern = "^Result_pheno-((field)|(patho))_(.*)_\\d{4}-\\d{2}-\\d{2}(_\\d)*\\.txt\\.gz$"
+      )
+    ))
+    return(c(truth_files, shared_files))
+  }))
+
+  # delete files
+  all_files <- c(
+    initial_files_truth,
+    initial_files_shared,
+    breeders_files
+  )
+  browser()
+  file.remove(all_files[file.exists(all_files)])
+
+  lapply(getBreederList(data_db), function(breeder) {
+    if (length(list.files(file.path(data_shared, breeder))) == 0) {
+      file.remove(file.path(data_shared, breeder))
+    } else {
+      stop(paste("can't remove", file.path(data_shared, breeder), "folder not empty."))
+    }
+    if (length(list.files(file.path(data_truth, breeder))) == 0) {
+      file.remove(file.path(data_truth, breeder))
+    } else {
+      stop(paste("can't remove", file.path(data_truth, breeder), "folder not empty."))
+    }
+  })
+
+  if (length(list.files(data_truth)) == 0) {
+    file.remove(data_truth)
+  } else {
+    stop(paste("can't remove", data_truth, "folder not empty."))
+  }
+  if (length(list.files(file.path(data_shared, "initial_data"))) == 0) {
+    file.remove(file.path(data_shared, "initial_data"))
+  } else {
+    stop(paste("can't remove", file.path(data_shared, "initial_data"), "folder not empty."))
+  }
+  if (length(list.files(data_shared)) == 0) {
+    file.remove(data_shared)
+  } else {
+    stop(paste("can't remove", data_shared, "folder not empty."))
+  }
+
+  file.remove(data_db)
+
+  if (length(list.files(data_root)) == 0) {
+    file.remove(data_root)
+  } else {
+    stop(paste("can't remove", data_root, "folder not empty."))
+  }
+}
diff --git a/src/server/server_admin.R b/src/server/server_admin.R
index 7a83b25..bd107d0 100644
--- a/src/server/server_admin.R
+++ b/src/server/server_admin.R
@@ -365,8 +365,8 @@ output$InfoCurrentMaxDiskUsage <- renderText({
 ## Game progress ----
 
 admin_gameProgressDta <- eventReactive(input$admin_progressButton, {
-  progressPheno <- shiny::Progress$new(session, min = 0, max = 4)
-  calcGameProgress(progressPheno)
+  progress_bar <- shiny::Progress$new(session, min = 0, max = 4)
+  calcGameProgress(progress_bar)
 })
 
 
@@ -546,3 +546,101 @@ output$admin_T1T2GameProgress <- renderPlotly({
       )
     )
 })
+
+
+
+output$initialisation_button <- renderUI({
+  if (!gameInitialised()) {
+    return(
+      actionButton("initialiseGame", "Initialise Game")
+    )
+  }
+
+  return(
+    div(
+      div(
+        h3("Important!"),
+        p(
+          "The game is already initialised. Reinitialising the game",
+          strong("will erase all the current game data"),
+          ". (All the breeders will be deleted along wiht their data.)"
+        ),
+        p("To reinitialise the game, write", code("plantbreedgame"), "in the", code("Confirmation"), "field below", "and click on the", code("Re-Initialise Game"), "button below.")
+      ),
+      div(
+        style = "display: table-row",
+        div(
+          style = "display: table-cell; padding-right: 5px;",
+          textInput("initialisation_security_text", label = "Confirmation:", value = "This action will erase all the data.")
+        ),
+        div(
+          style = "display: table-cell; padding-left: 5px; vertical-align: bottom",
+          actionButton("initialiseGame", "Re-Initialise Game")
+        )
+      )
+    )
+  )
+})
+
+observe({
+  if (identical(input$initialisation_security_text, "plantbreedgame")) {
+    shinyjs::enable("initialiseGame")
+    return(TRUE)
+  }
+  shinyjs::disable("initialiseGame")
+})
+
+
+observeEvent(input$initialiseGame, {
+  progress_bar <- shiny::Progress$new(session, min = 0, max = 1)
+
+  progress_bar$set(
+    value = 1 / 4,
+    message = "Game Initialisation:",
+    detail = "Initialisation..."
+  )
+  if (dir.exists(DATA_ROOT)) {
+    # WARN / TODO --- IMPORTANT ! ---
+    # the initialisation script do not allow its execution if "the data" folder
+    # already exists.
+    # Therefore here we will delete this folder, however, in general,
+    # IT IS QUITE RISKY to delete folder with code. For example:
+    # - if `DATA_ROOT` have been wrongly defined
+    # - if a malicious agent placed files/folder inside DATA_ROOT
+    # - if files are currently beeing created
+    #
+    # A better approach could be instead to only create a new `DATA_ROOT` folder
+    # and save in the data-base (that should only be erase, not deleted) the current
+    # `DATA_ROOT` to use.
+    # The server administrator would then responsible to safely remove the unecessary data.
+    #
+    # Here, to mitigate the risks the application will remove the files it
+    # has created (based on their names). This is not perfect as if one of this
+    # file have been is symlinked to another, the unintended file could be deleted.
+    #
+    # WARN / TODO --- IMPORTANT ! ---
+    progress_bar$set(
+      value = 1 / 4,
+      message = "Game Initialisation:",
+      detail = "Delete existing data..."
+    )
+    clean_data_root()
+  }
+  progress_bar$set(
+    value = 2 / 4,
+    message = "Game Initialisation:",
+    detail = "game setup..."
+  )
+  rmarkdown::render("./plantbreedgame_setup.Rmd",
+    output_file = "./plantbreedgame_setup.html",
+    encoding = "UTF-8"
+  )
+  progress_bar$set(
+    value = 1,
+    message = "Game Initialisation:",
+    detail = "Done"
+  )
+  alert("Game initialisation finished. This page will automatically refresh.")
+  gameInitialised()
+  shinyjs::refresh()
+})
diff --git a/src/ui/ui_admin_loggedIn.R b/src/ui/ui_admin_loggedIn.R
index 852fa31..39ce06e 100644
--- a/src/ui/ui_admin_loggedIn.R
+++ b/src/ui/ui_admin_loggedIn.R
@@ -23,316 +23,352 @@
 ## this file is sourced in "server_admin.R" in a renderUI() function
 ############################
 
-list(
-  shinydashboard::tabBox(
-    width = 12, title = "Admin", id = "admin_tabset", side = "left",
-    tabPanel(
-      "Manage sessions",
+
+
+if (gameInitialised()) {
+  manage_sessions_tab_content <- div(
+    div(
+      style = "margin-bottom:50px;",
+      h3("Current sessions:"),
+      tableOutput("sessionsTable")
+    ),
+    div( # add New session
       div(
-        style = "margin-bottom:50px;",
-        h3("Current sessions:"),
-        tableOutput("sessionsTable")
-      ),
-      div( # add New session
+        style = "margin-bottom: 20px;", # inputs
+        h3("Add a new session:"),
         div(
-          style = "margin-bottom: 20px;", # inputs
-          h3("Add a new session:"),
-          div(
-            style = "display: inline-block; vertical-align:top; width: 33%; min-width:300px;", # start
-            h4("Start"),
-            tags$table(
-              style = "width: 300px; border-collapse: collapse;", # start table 1
-              tags$td(
-                style = "width: 34%; vertical-align: bottom; padding: 10px; padding-bottom: 13.8px;",
-                dateInput("startDate", "date",
-                  width = "100px"
-                )
-              ),
-              tags$td(
-                style = "width: 33%; vertical-align: bottom; padding: 10px; padding-bottom: 13.8px;",
-                numericInput("startHour", "hour",
-                  value = 9, min = 0, max = 23, step = 1,
-                  width = "75px"
-                )
-              ),
-              tags$td(
-                style = "width: 33%; vertical-align: bottom; padding: 10px; padding-bottom: 13.8px;",
-                numericInput("startMin", "minute",
-                  value = 0, min = 0, max = 59, step = 1,
-                  width = "75px"
-                )
+          style = "display: inline-block; vertical-align:top; width: 33%; min-width:300px;", # start
+          h4("Start"),
+          tags$table(
+            style = "width: 300px; border-collapse: collapse;", # start table 1
+            tags$td(
+              style = "width: 34%; vertical-align: bottom; padding: 10px; padding-bottom: 13.8px;",
+              dateInput("startDate", "date",
+                width = "100px"
               )
-            ) # end table 1
-          ), # end div "start"
-
-          div(
-            style = "display: inline-block; vertical-align:top; width: 33%; min-width:300px;", # end
-            h4("End"),
-            tags$table(
-              style = "width: 300px; border-collapse: collapse;", # start table 2
-              tags$td(
-                style = "width: 34%; vertical-align: bottom; padding: 10px; padding-bottom: 13.8px;",
-                dateInput("endDate", "date",
-                  width = "100px"
-                )
-              ),
-              tags$td(
-                style = "width: 33%; vertical-align: bottom; padding: 10px; padding-bottom: 13.8px;",
-                numericInput("endHour", "hour",
-                  value = 9, min = 0, max = 23, step = 1,
-                  width = "75px"
-                )
-              ),
-              tags$td(
-                style = "width: 33%; vertical-align: bottom; padding: 10px; padding-bottom: 13.8px;",
-                numericInput("endMin", "minute",
-                  value = 0, min = 0, max = 59, step = 1,
-                  width = "75px"
-                )
+            ),
+            tags$td(
+              style = "width: 33%; vertical-align: bottom; padding: 10px; padding-bottom: 13.8px;",
+              numericInput("startHour", "hour",
+                value = 9, min = 0, max = 23, step = 1,
+                width = "75px"
               )
-            ) # end table 2
-          ), # end div "end"
-
-          div(
-            style = "display: inline-block; vertical-align:top; width:33%; min-width:300px;", # year time
-            h4("Year time"),
-            tags$table(
-              style = "border-collapse: collapse;", # start table 3
-              tags$td(
-                style = "width: 33%; vertical-align: bottom; padding: 10px; padding-bottom: 13.8px;",
-                numericInput("yearTime", "Duration of one year (in minutes)", value = 60, min = 0, max = Inf, step = 1)
+            ),
+            tags$td(
+              style = "width: 33%; vertical-align: bottom; padding: 10px; padding-bottom: 13.8px;",
+              numericInput("startMin", "minute",
+                value = 0, min = 0, max = 59, step = 1,
+                width = "75px"
               )
-            ) # end table 3
-          ) # end div "year time"
-        ), # end div inputs
-
-        div(
-          style = "display: inline-block; vertical-align:top; width:25%; margin-bottom: 50px; padding-left: 10px;", # button
-          actionButton("addSession", "Add this new session")
-        ) # end div "button"
-      ), # end div "add New session"
-
-
-
-      div(
-        style = "margin-bottom:100px;", # delete session
-        h3("Delete sessions:"),
-        tags$table(
-          style = "width: 100%; border-collapse: collapse;",
-          tags$td(
-            style = "width: 50%; vertical-align: bottom; padding: 10px;",
-            selectInput("delSession", "Session's number",
-              choices = c("", sessionsList()$num),
-              selected = "", width = "100%"
-            )
-          ),
-          tags$td(
-            style = "width: 50%; vertical-align: bottom; padding: 10px; padding-bottom: 13.8px;",
-            actionButton("deleteSession", "DO NOT click! (unless you are sure to delete this session)",
-              width = "100%", style = "margin-bottom: 0px;",
-              style = "background-color:#ff3333; color:white;"
             )
-          )
-        )
-      ) # end div "delete session"
-    ), # end tabPanel sessions managment
-
-
-
-
-
+          ) # end table 1
+        ), # end div "start"
 
-    tabPanel(
-      "Manage breeders",
-      div( # add New breeders
-        h3("Add a new breeder:"),
-        tags$head(
-          tags$style(HTML(".shiny-input-container{margin-bottom: 0px;}
-                                                            .selectize-control{margin-bottom: 0px;}"))
-        ),
-        tags$table(
-          style = "width: 100%; border-collapse: collapse;",
-          tags$tr(
-            tags$td(
-              style = "width: 25%; vertical-align: bottom; padding: 10px; padding-bottom: 13.8px;",
-              textInput("newBreederName", "Breeder's name",
-                placeholder = "Only a-z, A-Z, 0-9 and '_' are allowed",
-                width = "100%"
-              )
-            ),
+        div(
+          style = "display: inline-block; vertical-align:top; width: 33%; min-width:300px;", # end
+          h4("End"),
+          tags$table(
+            style = "width: 300px; border-collapse: collapse;", # start table 2
             tags$td(
-              style = "width: 25%; vertical-align: bottom; padding: 10px;",
-              selectInput("newBreederStatus", "Status",
-                choices = c("player", "tester", "game master"),
-                width = "100%"
+              style = "width: 34%; vertical-align: bottom; padding: 10px; padding-bottom: 13.8px;",
+              dateInput("endDate", "date",
+                width = "100px"
               )
             ),
             tags$td(
-              style = "width: 25%; vertical-align: bottom; padding: 10px; padding-bottom: 13.8px;",
-              passwordInput("newBreederPsw", "Password",
-                width = "100%"
+              style = "width: 33%; vertical-align: bottom; padding: 10px; padding-bottom: 13.8px;",
+              numericInput("endHour", "hour",
+                value = 9, min = 0, max = 23, step = 1,
+                width = "75px"
               )
             ),
             tags$td(
-              style = "width: 25%; vertical-align: bottom; padding: 10px; padding-bottom: 13.8px;",
-              actionButton("addNewBreeder", "Add this new breeder",
-                width = "100%", style = "margin-bottom: 0px;"
+              style = "width: 33%; vertical-align: bottom; padding: 10px; padding-bottom: 13.8px;",
+              numericInput("endMin", "minute",
+                value = 0, min = 0, max = 59, step = 1,
+                width = "75px"
               )
             )
-          )
-        ) # end tags$table
-      ), # end div "add new breeder"
+          ) # end table 2
+        ), # end div "end"
 
+        div(
+          style = "display: inline-block; vertical-align:top; width:33%; min-width:300px;", # year time
+          h4("Year time"),
+          tags$table(
+            style = "border-collapse: collapse;", # start table 3
+            tags$td(
+              style = "width: 33%; vertical-align: bottom; padding: 10px; padding-bottom: 13.8px;",
+              numericInput("yearTime", "Duration of one year (in minutes)", value = 60, min = 0, max = Inf, step = 1)
+            )
+          ) # end table 3
+        ) # end div "year time"
+      ), # end div inputs
 
-      div( # delete breeders
-        h3("Delete a breeder:"),
-        tags$table(
-          style = "width: 100%; border-collapse: collapse;",
+      div(
+        style = "display: inline-block; vertical-align:top; width:25%; margin-bottom: 50px; padding-left: 10px;", # button
+        actionButton("addSession", "Add this new session")
+      ) # end div "button"
+    ), # end div "add New session"
+
+
+
+    div(
+      style = "margin-bottom:100px;", # delete session
+      h3("Delete sessions:"),
+      tags$table(
+        style = "width: 100%; border-collapse: collapse;",
+        tags$td(
+          style = "width: 50%; vertical-align: bottom; padding: 10px;",
+          selectInput("delSession", "Session's number",
+            choices = c("", sessionsList()$num),
+            selected = "", width = "100%"
+          )
+        ),
+        tags$td(
+          style = "width: 50%; vertical-align: bottom; padding: 10px; padding-bottom: 13.8px;",
+          actionButton("deleteSession", "DO NOT click! (unless you are sure to delete this session)",
+            width = "100%", style = "margin-bottom: 0px;",
+            style = "background-color:#ff3333; color:white;"
+          )
+        )
+      )
+    ) # end div "delete session"
+  )
+
+  manage_breeders_tab_content <- div(
+    div( # add New breeders
+      h3("Add a new breeder:"),
+      tags$head(
+        tags$style(HTML(".shiny-input-container{margin-bottom: 0px;}
+          .selectize-control{margin-bottom: 0px;}"))
+      ),
+      tags$table(
+        style = "width: 100%; border-collapse: collapse;",
+        tags$tr(
+          tags$td(
+            style = "width: 25%; vertical-align: bottom; padding: 10px; padding-bottom: 13.8px;",
+            textInput("newBreederName", "Breeder's name",
+              placeholder = "Only a-z, A-Z, 0-9 and '_' are allowed",
+              width = "100%"
+            )
+          ),
           tags$td(
-            style = "width: 50%; vertical-align: bottom; padding: 10px;",
-            breeder_list_ui("admin_breeder_list_for_deletion"),
+            style = "width: 25%; vertical-align: bottom; padding: 10px;",
+            selectInput("newBreederStatus", "Status",
+              choices = c("player", "tester", "game master"),
+              width = "100%"
+            )
+          ),
+          tags$td(
+            style = "width: 25%; vertical-align: bottom; padding: 10px; padding-bottom: 13.8px;",
+            passwordInput("newBreederPsw", "Password",
+              width = "100%"
+            )
           ),
           tags$td(
-            style = "width: 50%; vertical-align: bottom; padding: 10px; padding-bottom: 13.8px;",
-            actionButton("deleteBreeder", "DO NOT click! (unless you are sure to delete this breeder)",
-              width = "100%", style = "margin-bottom: 0px;",
-              style = "background-color:#ff3333; color:white;"
+            style = "width: 25%; vertical-align: bottom; padding: 10px; padding-bottom: 13.8px;",
+            actionButton("addNewBreeder", "Add this new breeder",
+              width = "100%", style = "margin-bottom: 0px;"
             )
           )
         )
-      ) # end div "delete breeders"
-    ), # end tabPanel "Add/Delete Breeders"
+      ) # end tags$table
+    ), # end div "add new breeder"
 
 
-    tabPanel(
-      "Manage constants",
-      # tabPanel to manage some game constants
-
-      # see.year.effct
-      div(
-        id = "admin_seedYearEffect",
-        style = "margin: 0px 0px 40px 0px;",
-
-        # input:
-        div(
-          id = "admin_div_numInput_seedYearEfect",
-          style = "display: inline-block;
-                     vertical-align: top;",
-          numericInput("admin_seedYearEfect", "seed.year.effect",
-            value = 4321,
-            min = 0,
-            max = NA,
-            step = 1
-          )
-        ),
-
-        # button to request update:
-        div(
-          id = "admin_div_button_seedYearEfect",
-          style = "display: inline-block;
-                     vertical-align: top;
-                     padding-top: 25px", # button align with numInput
-          actionButton("admin_button_seedYearEfect", "update seed.year.effect")
+    div( # delete breeders
+      h3("Delete a breeder:"),
+      tags$table(
+        style = "width: 100%; border-collapse: collapse;",
+        tags$td(
+          style = "width: 50%; vertical-align: bottom; padding: 10px;",
+          breeder_list_ui("admin_breeder_list_for_deletion"),
         ),
-
-        # current value:
-        div(
-          id = "admin_currentSYE",
-          "Current", code("seed.year.effect"), ":", textOutput("admin_currentSYE", container = span)
+        tags$td(
+          style = "width: 50%; vertical-align: bottom; padding: 10px; padding-bottom: 13.8px;",
+          actionButton("deleteBreeder", "DO NOT click! (unless you are sure to delete this breeder)",
+            width = "100%", style = "margin-bottom: 0px;",
+            style = "background-color:#ff3333; color:white;"
+          )
         )
-      ) # end div "admin_seedYearEffect"
-    ), # end tabPanel "Manage constants"
-
-
+      )
+    ) # end div "delete breeders"
+  )
 
 
+  manage_constants_tab_content <- div(
+    div(
+      id = "admin_seedYearEffect",
+      style = "margin: 0px 0px 40px 0px;",
 
-
-
-    tabPanel(
-      "Disk usage",
+      # input:
       div(
-        id = "admin_diskU_data",
+        id = "admin_div_numInput_seedYearEfect",
         style = "display: inline-block;
-                 vertical-align:top;
-                 width: 33%;
-                 min-width:300px;",
-        h3("Disk usage:"),
-        tableOutput("sizeDataFolder")
+        vertical-align: top;",
+        numericInput("admin_seedYearEfect", "seed.year.effect",
+          value = 4321,
+          min = 0,
+          max = NA,
+          step = 1
+        )
       ),
+
+      # button to request update:
       div(
-        id = "admin_diskU_input",
+        id = "admin_div_button_seedYearEfect",
         style = "display: inline-block;
-                 vertical-align:top;
-                 width: 66%;",
-        p("To prevent over disk usage on your server, you can specifiy here the maximum size for all game data.",
-          style = "margin-top:20px;"
-        ),
-        p("In case the size of all data exceeds this threshold, players will not be allowed to connect any more, and you will have to delete haplotypes of some breeders."),
-        p(textOutput("InfoCurrentMaxDiskUsage")),
-        div(
-          style = "width: 50%;
-                     display: inline-block;
-                     vertical-align: top;",
-          numericInput("admin_maxDiskUsage",
-            label = "Maximum disk usage (in Gb)",
-            value = 10,
-            min = 2
-          )
+        vertical-align: top;
+        padding-top: 25px", # button align with numInput
+        actionButton("admin_button_seedYearEfect", "update seed.year.effect")
+      ),
+
+      # current value:
+      div(
+        id = "admin_currentSYE",
+        "Current", code("seed.year.effect"), ":", textOutput("admin_currentSYE", container = span)
+      )
+    ) # end div "admin_seedYearEffect"
+  )
+
+  disk_usage_tab_content <- div(
+    div(
+      id = "admin_diskU_data",
+      style = "display: inline-block;
+      vertical-align:top;
+      width: 33%;
+      min-width:300px;",
+      h3("Disk usage:"),
+      tableOutput("sizeDataFolder")
+    ),
+    div(
+      id = "admin_diskU_input",
+      style = "display: inline-block;
+      vertical-align:top;
+      width: 66%;",
+      p("To prevent over disk usage on your server, you can specifiy here the maximum size for all game data.",
+        style = "margin-top:20px;"
+      ),
+      p("In case the size of all data exceeds this threshold, players will not be allowed to connect any more, and you will have to delete haplotypes of some breeders."),
+      p(textOutput("InfoCurrentMaxDiskUsage")),
+      div(
+        style = "width: 50%;
+        display: inline-block;
+        vertical-align: top;",
+        numericInput("admin_maxDiskUsage",
+          label = "Maximum disk usage (in Gb)",
+          value = 10,
+          min = 2
+        )
+      ),
+      div(
+        style = "width: 30%;
+        padding-top: 26px;
+        display: inline-block;
+        vertical-align: top;",
+        actionButton("updateMaxDiskUsage",
+          label = "Update"
+        )
+      )
+    ) # end div "admin_diskU_input"
+  )
+
+
+  game_progress_tab_content <- div(
+    fluidRow(
+      div(
+        class = "col-sm-12 col-md-12 col-lg-12",
+        selectInput(
+          inputId = "admin_progressTrait",
+          label = "Trait",
+          choices = c("Trait 1", "Trait 2"),
+          selected = "Trait 1"
         ),
-        div(
-          style = "width: 30%;
-                     padding-top: 26px;
-                     display: inline-block;
-                     vertical-align: top;",
-          actionButton("updateMaxDiskUsage",
-            label = "Update"
-          )
+        actionButton(
+          inputId = "admin_progressButton",
+          label = "Refresh !",
+          icon = icon("refresh"),
+          style = "background-color: #00a65a;
+          color: #ffffff;"
         )
-      ) # end div "admin_diskU_input"
-    ), # end tabPanel "Disk usage"
+      ),
+      div(
+        class = "col-sm-12 col-md-12 col-lg-6",
+        plotlyOutput("admin_plotAllIndGameProgress") %>% withSpinner()
+      ),
+      div(
+        class = "col-sm-12 col-md-12 col-lg-6",
+        plotlyOutput("admin_plotMaxIndGameProgress") %>% withSpinner()
+      ),
+      div(
+        class = "col-sm-12 col-md-12 col-lg-6",
+        plotlyOutput("admin_boxPlotGameProgress") %>% withSpinner()
+      ),
+      div(
+        class = "col-sm-12 col-md-12 col-lg-6",
+        breeder_list_ui("admin_breeder_list_gameProgress"),
+        plotlyOutput("admin_T1T2GameProgress") %>% withSpinner()
+      )
+    ) # end fluidRow
+  )
+
+
+} else {
+  game_not_initialised_msg <- div(
+    h3("Game not initialised"),
+    p("The game have not been initialised. It is therefore currently impossible to play.")
+  )
+  manage_sessions_tab_content <- game_not_initialised_msg
+  manage_breeders_tab_content <- game_not_initialised_msg
+  manage_constants_tab_content <- game_not_initialised_msg
+  disk_usage_tab_content <- game_not_initialised_msg
+  game_progress_tab_content <- game_not_initialised_msg
+}
+
+
+game_initialisation_tab_content <- div(
+  p("By pressing the button below, you can initialise the game."),
+  p("Once the initialisation is completed (which takes about 2 minutes), the page will automatically reload and you will be able to connect and play the game."),
+  div(
+    h2("Information:"),
+    p("Some breeders accounts will be automatically created:"),
+    tags$ul(
+      tags$li(code("Admin"), "with the default password", code("1234")),
+      tags$li(code("Tester"), "(this breeder do not have a password, you can leave the password field empty to connect)")
+    )
+  ),
+  uiOutput("initialisation_button")
+)
 
 
 
-    #----- Game progress -----
-    # This tab displays the progression of the players.
+list(
+  shinydashboard::tabBox(
+    width = 12, title = "Admin", id = "admin_tabset", side = "left",
+    tabPanel(
+      "Manage sessions",
+      manage_sessions_tab_content
+    ),
+    tabPanel(
+      "Manage breeders",
+      manage_breeders_tab_content
+    ),
+    tabPanel(
+      "Manage constants",
+      manage_constants_tab_content
+    ),
+    tabPanel(
+      "Disk usage",
+      disk_usage_tab_content
+    ),
     tabPanel(
       "Game progress",
-      fluidRow(
-        div(
-          class = "col-sm-12 col-md-12 col-lg-12",
-          selectInput(
-            inputId = "admin_progressTrait",
-            label = "Trait",
-            choices = c("Trait 1", "Trait 2"),
-            selected = "Trait 1"
-          ),
-          actionButton(
-            inputId = "admin_progressButton",
-            label = "Refresh !",
-            icon = icon("refresh"),
-            style = "background-color: #00a65a;
-                                      color: #ffffff;"
-          )
-        ),
-        div(
-          class = "col-sm-12 col-md-12 col-lg-6",
-          plotlyOutput("admin_plotAllIndGameProgress") %>% withSpinner()
-        ),
-        div(
-          class = "col-sm-12 col-md-12 col-lg-6",
-          plotlyOutput("admin_plotMaxIndGameProgress") %>% withSpinner()
-        ),
-        div(
-          class = "col-sm-12 col-md-12 col-lg-6",
-          plotlyOutput("admin_boxPlotGameProgress") %>% withSpinner()
-        ),
-        div(
-          class = "col-sm-12 col-md-12 col-lg-6",
-          breeder_list_ui("admin_breeder_list_gameProgress"),
-          plotlyOutput("admin_T1T2GameProgress") %>% withSpinner()
-        )
-      ) # end fluidRow
-    ) # end tabPanel "Game progress"
-  ) # close tabBox
-) # close list
+      game_progress_tab_content
+    ),
+    tabPanel(
+      "Game Initialisation",
+      game_initialisation_tab_content
+    )
+  )
+)
diff --git a/tests_UI/test-1.spec.ts b/tests_UI/test-1.spec.ts
index be0df3e..e46655a 100644
--- a/tests_UI/test-1.spec.ts
+++ b/tests_UI/test-1.spec.ts
@@ -130,6 +130,11 @@ test.describe("PlantBreedGame_UI", () => {
 
     await runEvaluation(page, registered_inds);
   });
+
+  // TODO add tests related to  game initialisation
+
+  // TODO add tests where several requests are made with the same file
+  // this is a edge case that could happend
 });
 
 async function login(page: Page, username: string, password: string) {