diff --git a/src/battle.c b/src/battle.c
index fb91a1998..01b865d61 100644
--- a/src/battle.c
+++ b/src/battle.c
@@ -1539,6 +1539,17 @@ static int get_tactics(const side * as, const side * ds)
     return result - defense;
 }
 
+double tactics_chance(const unit *u, int skilldiff) {
+    double tacch = 0.1 * skilldiff;
+    if (fval(u->region->terrain, SEA_REGION)) {
+        const ship *sh = u->ship;
+        if (sh) {
+            tacch *= sh->type->tac_bonus;
+        }
+    }
+    return tacch;
+}
+
 static troop select_opponent(battle * b, troop at, int mindist, int maxdist)
 {
     fighter *af = at.fighter;
@@ -1560,12 +1571,7 @@ static troop select_opponent(battle * b, troop at, int mindist, int maxdist)
 
             /* percentage chance to get this attack */
             if (tactics > 0) {
-                double tacch = 0.1 * tactics;
-                if (fval(b->region->terrain, SEA_REGION)) {
-                    ship *sh = at.fighter->unit->ship;
-                    if (sh)
-                        tacch *= sh->type->tac_bonus;
-                }
+                double tacch = tactics_chance(af->unit, tactics);
                 if (!chance(tacch)) {
                     dt.fighter = NULL;
                 }
diff --git a/src/battle.h b/src/battle.h
index f2dd1fea3..c9429a6b3 100644
--- a/src/battle.h
+++ b/src/battle.h
@@ -270,6 +270,7 @@ extern "C" {
     const char *sidename(const struct side * s);
     void battle_message_faction(struct battle * b, struct faction * f, struct message *m);
 
+    double tactics_chance(const struct unit *u, int skilldiff);
 #ifdef __cplusplus
 }
 #endif
diff --git a/src/battle.test.c b/src/battle.test.c
index f293f967d..56ca24ac4 100644
--- a/src/battle.test.c
+++ b/src/battle.test.c
@@ -10,6 +10,7 @@
 #include <kernel/item.h>
 #include <kernel/race.h>
 #include <kernel/region.h>
+#include <kernel/ship.h>
 #include <kernel/unit.h>
 
 #include <spells/buildingcurse.h>
@@ -665,6 +666,22 @@ static void test_drain_exp(CuTest *tc)
     test_teardown();
 }
 
+static void test_tactics_chance(CuTest *tc) {
+    unit *u;
+    ship_type *stype;
+
+    test_setup();
+    u = test_create_unit(test_create_faction(NULL), test_create_ocean(0, 0));
+    CuAssertDblEquals(tc, 0.1, tactics_chance(u, 1), 0.01);
+    CuAssertDblEquals(tc, 0.3, tactics_chance(u, 3), 0.01);
+    stype = test_create_shiptype("brot");
+    u->ship = test_create_ship(u->region, stype);
+    CuAssertDblEquals(tc, 0.2, tactics_chance(u, 2), 0.01);
+    stype->tac_bonus = 2.0;
+    CuAssertDblEquals(tc, 0.4, tactics_chance(u, 2), 0.01);
+    test_teardown();
+}
+
 CuSuite *get_battle_suite(void)
 {
     CuSuite *suite = CuSuiteNew();
@@ -681,6 +698,7 @@ CuSuite *get_battle_suite(void)
     SUITE_ADD_TEST(suite, test_natural_armor);
     SUITE_ADD_TEST(suite, test_magic_resistance);
     SUITE_ADD_TEST(suite, test_projectile_armor);
+    SUITE_ADD_TEST(suite, test_tactics_chance);
     DISABLE_TEST(suite, test_drain_exp);
     return suite;
 }