diff --git a/README.md b/README.md
index 4613a62..6795d56 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,7 @@
 Usage:
 
 `./odds.py [num_dice [sides_on_dice [monte_carlo_runs]]] [debug] [no_mc] [simple]`
+
+debug = print debug info
+no_mc = don't run stochastic verification
+simple = just output the odds number, no user-readable text