Changes

diff --git a/prompts.md b/prompts.md
index 44c01cf..5285b66 100644
--- a/prompts.md
+++ b/prompts.md
@@ -43,5 +43,10 @@ an emoji on it.
 
 ----
 
-
-TODO: show list of discarded cards
+Right now the game allows infinite undos. We should change that to
+only allow 1 undo (the player can still undo multiple times, but they
+can only go back by 1 step). However, don't complete remove the
+history stack. Create a global (or put it in other scope as you see
+fit) constant to indicate how many steps the player can go back. This
+way we could easily change it in the future. Don't expose this setting
+in the UI.