diff --git a/01_text_adventure/data/flags.txt b/01_text_adventure/data/flags.txt
index deda289..bdf054b 100644
--- a/01_text_adventure/data/flags.txt
+++ b/01_text_adventure/data/flags.txt
@@ -1,2 +1,2 @@
 LEVER_PULLED|0
-STEPS_TAKEN|0
+STEPS_TAKEN|10
diff --git a/01_text_adventure/game.c b/01_text_adventure/game.c
index d1aebcf..0cef2cf 100644
--- a/01_text_adventure/game.c
+++ b/01_text_adventure/game.c
@@ -9,6 +9,7 @@
 #include "util.h"
 #include "word.h"
 #include "flag.h"
+#include "predicate.h"
 
 Game *game_create(void) {
   Game *g = malloc(sizeof(Game));
@@ -125,6 +126,37 @@ void game_handle_command(Game *g, const char *command) {
     free(response);
     break;
   }
+
+  Predicate fr;
+  fr.type = PREDICATE_IN_ROOM;
+  fr.argument = "FIRST_ROOM";
+  printf("in room FIRST_ROOM: %d\n", predicate_fulfilled(g, &fr));
+
+  Predicate sr;
+  sr.type = PREDICATE_IN_ROOM;
+  sr.argument = "SECOND_ROOM";
+  printf("in room SECOND_ROOM: %d\n", predicate_fulfilled(g, &sr));
+
+  Predicate lr;
+  lr.type = PREDICATE_IN_ROOM;
+  lr.argument = "LAST_ROOM";
+  printf("in room LAST_ROOM: %d\n", predicate_fulfilled(g, &lr));
+
+  Predicate tr;
+  tr.type = PREDICATE_TRUE;
+  printf("true: %d\n", predicate_fulfilled(g, &tr));
+
+  Predicate lf;
+  lf.type = PREDICATE_FLAG_ENABLED;
+  lf.argument = "LEVER_PULLED";
+  printf("lever pulled: %d\n", predicate_fulfilled(g, &lf));
+
+  Predicate sf;
+  sf.type = PREDICATE_FLAG_ENABLED;
+  sf.argument = "STEPS_TAKEN";
+  printf("steps_taken: %d\n", predicate_fulfilled(g, &sf));
+
+  printf("\n");
 }
 
 void game_handle_input(Game *g) {
diff --git a/01_text_adventure/predicate.c b/01_text_adventure/predicate.c
new file mode 100644
index 0000000..73e60f4
--- /dev/null
+++ b/01_text_adventure/predicate.c
@@ -0,0 +1,19 @@
+#include <stdio.h>
+#include <string.h>
+#include "game.h"
+#include "flag.h"
+#include "predicate.h"
+
+bool predicate_fulfilled(Game *g, Predicate *p) {
+  switch (p->type) {
+  case PREDICATE_TRUE:
+    return true;
+  case PREDICATE_IN_ROOM:
+    return strcmp(g->current_room->name, p->argument) == 0;
+  case PREDICATE_FLAG_ENABLED:
+    return flag_value(g->flags, p->argument) > 0;
+  default:
+    printf("Invalid predicate type\n");
+    return false;
+  }
+}
diff --git a/01_text_adventure/predicate.h b/01_text_adventure/predicate.h
new file mode 100644
index 0000000..7ca0538
--- /dev/null
+++ b/01_text_adventure/predicate.h
@@ -0,0 +1,22 @@
+#ifndef _FD_PREDICATE_
+#define _FD_PREDICATE_
+
+typedef struct Predicate Predicate;
+
+typedef enum PredicateType {
+  PREDICATE_TRUE,
+  PREDICATE_IN_ROOM,
+  // PREDICATE_HAS_ITEM,
+  PREDICATE_FLAG_ENABLED,
+} PredicateType;
+
+#include "game.h"
+
+struct Predicate {
+  PredicateType type;
+  char *argument;
+};
+
+bool predicate_fulfilled(Game *g, Predicate *p);
+
+#endif