diff --git a/src/client/serverio.c b/src/client/serverio.c
index 9741413b..93420c5b 100644
--- a/src/client/serverio.c
+++ b/src/client/serverio.c
@@ -76,7 +76,7 @@ serverio(int s, struct ioqueue *ioq)
 	return 0;
     }
     if (n != ioq->bsize)
-	buf = (char *)realloc(buf, n);
+	buf = realloc(buf, n);
     ioq_write(ioq, buf, n);
     return 1;
 }
diff --git a/src/lib/commands/buy.c b/src/lib/commands/buy.c
index d2962b69..2188239b 100644
--- a/src/lib/commands/buy.c
+++ b/src/lib/commands/buy.c
@@ -112,7 +112,7 @@ buy(void)
     bid = atof(p);
     if (bid <= 0)
 	return RET_FAIL;
-    if (natp->nat_money < (bid * comm.com_amount * buytax)) {
+    if (natp->nat_money < bid * comm.com_amount * buytax) {
 	pr("This purchase would cost %.2f, %.2f more than you have.\n",
 	   bid * comm.com_amount * buytax,
 	   bid * comm.com_amount * buytax - natp->nat_money);
@@ -131,12 +131,12 @@ buy(void)
     for (q = 0; getcomm(q, &comt); q++) {
 	if (comt.com_maxbidder == player->cnum &&
 	    comt.com_owner != 0 && comt.com_owner != player->cnum) {
-	    tally += (comt.com_price * comt.com_amount) * buytax;
+	    tally += comt.com_price * comt.com_amount * buytax;
 	}
     }
     canspend = natp->nat_money - tally;
     getcomm(o, &comm);
-    if ((bid * comm.com_amount * buytax) > canspend) {
+    if (bid * comm.com_amount * buytax > canspend) {
 	pr("You have overextended yourself in the market\n");
 	pr("You can not bid on the current items at that price.\n");
 	return RET_OK;
@@ -165,7 +165,7 @@ buy(void)
 	   qty, ip->i_name, n);
 	return RET_FAIL;
     }
-    if ((bid * comm.com_amount) > natp->nat_money) {
+    if (bid * comm.com_amount > natp->nat_money) {
 	pr("You don't have that much to spend!\n");
 	return RET_FAIL;
     }
diff --git a/src/lib/commands/look.c b/src/lib/commands/look.c
index 137fb0c5..c0329de6 100644
--- a/src/lib/commands/look.c
+++ b/src/lib/commands/look.c
@@ -260,7 +260,7 @@ look_land(struct lndstr *lookland)
     int dist;
 
     drange = techfact(lookland->lnd_tech, lookland->lnd_spy);
-    drange = (drange * ((double)lookland->lnd_effic / 100.0));
+    drange *= lookland->lnd_effic / 100.0;
     range = ldround(drange, 1);
 
     if (range == 0)
diff --git a/src/lib/commands/mfir.c b/src/lib/commands/mfir.c
index e645b79d..fc362ef9 100644
--- a/src/lib/commands/mfir.c
+++ b/src/lib/commands/mfir.c
@@ -364,7 +364,7 @@ multifire(void)
 	    shots = gun;
 	    guneff = seagun(fship.shp_effic, shots);
 	    dam = (int)guneff;
-	    shell -= ldround(((double)shots) / 2.0, 1);
+	    shell -= ldround(shots / 2.0, 1);
 	    fship.shp_item[I_SHELL] = shell;
 	    if (opt_NOMOBCOST == 0)
 		fship.shp_mobil = MAX(fship.shp_mobil - 15, -100);
@@ -414,8 +414,8 @@ multifire(void)
 	    dam = (int)landunitgun(fland.lnd_effic, fland.lnd_dam, gun,
 				   fland.lnd_ammo, shell);
 	    if (target == targ_ship) {
-		if (chance(((double)fland.lnd_acc) / 100.0))
-		    dam = ldround(((double)dam / 2.0), 1);
+		if (chance(fland.lnd_acc / 100.0))
+		    dam = ldround(dam / 2.0, 1);
 	    }
 	    use_supply(&fland);
 	    resupply_commod(&fland, I_SHELL);	/* Get more shells */
@@ -554,7 +554,7 @@ multifire(void)
 	    prb *= prb;
 	    if (chance(prb)) {
 		pr("Wind deflects shell%s.\n", splur(shots));
-/*			dam = (int)((double)dam / 2.0);*/
+/*			dam = (int)(dam / 2.0);*/
 		dam *= (90 - (random() % 11)) / 100.0;
 		if (dam < 0)
 		    dam = 0;
@@ -713,7 +713,7 @@ do_defdam(struct emp_qelem *list, double odds)
 	    pr("\nDefenders fire back!\n");
 	    first = 0;
 	}
-	dam = (odds * (double)fp->defdam);
+	dam = odds * fp->defdam;
 
 	if (fp->type == targ_ship) {
 	    vict = fp->victim;
diff --git a/src/lib/commands/miss.c b/src/lib/commands/miss.c
index d0d3263c..8e896e40 100644
--- a/src/lib/commands/miss.c
+++ b/src/lib/commands/miss.c
@@ -209,7 +209,7 @@ mission(void)
 	return RET_FAIL;
     }
 
-    mobused = ldround((mission_mob_cost * (double)mobmax), 1);
+    mobused = ldround(mission_mob_cost * (double)mobmax, 1);
 
     while (nxtitem(&ni, &item)) {
 	gp = (struct genitem *)&item;
diff --git a/src/lib/commands/rada.c b/src/lib/commands/rada.c
index 3de1333f..363246dd 100644
--- a/src/lib/commands/rada.c
+++ b/src/lib/commands/rada.c
@@ -75,10 +75,10 @@ rada(void)
 	if (!snxtsct(&ns, cp))
 	    return RET_SYN;
 	tech = tfact(player->cnum, 8.0);
-	if (tech > ((double)WORLD_Y / 4.0))
-	    tech = ((double)WORLD_Y / 4.0);
-	if (tech > ((double)WORLD_X / 8.0))
-	    tech = ((double)WORLD_X / 8.0);
+	if (tech > WORLD_Y / 4.0)
+	    tech = WORLD_Y / 4.0;
+	if (tech > WORLD_X / 8.0)
+	    tech = WORLD_X / 8.0;
 	while (nxtsct(&ns, &sect)) {
 	    if (sect.sct_type != SCT_RADAR)
 		continue;
@@ -105,11 +105,11 @@ rada(void)
 		    tf = 0.0;
 		pr("%s at ", prship(&ship));
 		tech = techfact(ship.shp_tech,
-				(double)mchr[(int)ship.shp_type].m_vrnge);
-		if (tech > ((double)WORLD_Y / 2.0))
-		    tech = ((double)WORLD_Y / 2.0);
-		if (tech > ((double)WORLD_X / 4.0))
-		    tech = ((double)WORLD_X / 4.0);
+				mchr[(int)ship.shp_type].m_vrnge);
+		if (tech > WORLD_Y / 2.0)
+		    tech = WORLD_Y / 2.0;
+		if (tech > WORLD_X / 4.0)
+		    tech = WORLD_X / 4.0;
 		radmap(ship.shp_x, ship.shp_y, ship.shp_effic,
 		       (int)tech, tf);
 	    }
@@ -133,10 +133,10 @@ rada(void)
 		tf = 0.0;
 		pr("%s at ", prland(&land));
 		tech = techfact(land.lnd_tech, land.lnd_spy);
-		if (tech > ((double)WORLD_Y / 2.0))
-		    tech = ((double)WORLD_Y / 2.0);
-		if (tech > ((double)WORLD_X / 4.0))
-		    tech = ((double)WORLD_X / 4.0);
+		if (tech > WORLD_Y / 2.0)
+		    tech = WORLD_Y / 2.0;
+		if (tech > WORLD_X / 4.0)
+		    tech = WORLD_X / 4.0;
 		radmap(land.lnd_x, land.lnd_y, land.lnd_effic,
 		       (int)tech, tf);
 	    }
diff --git a/src/lib/commands/spy.c b/src/lib/commands/spy.c
index 640fd94a..fd550bc0 100644
--- a/src/lib/commands/spy.c
+++ b/src/lib/commands/spy.c
@@ -152,7 +152,7 @@ spy(void)
 		continue;
 	    }
 	    /* catch spy N/200 chance, N = # military */
-	    caught = chance((double)dsect.sct_item[I_MILIT] / 200.0);
+	    caught = chance(dsect.sct_item[I_MILIT] / 200.0);
 	    own = dsect.sct_own;
 	    /* determine spyee relations with spyer */
 	    relat = getrel(getnatp(own), player->cnum);
diff --git a/src/lib/commands/torp.c b/src/lib/commands/torp.c
index 747faabf..2a8e22ca 100644
--- a/src/lib/commands/torp.c
+++ b/src/lib/commands/torp.c
@@ -346,7 +346,7 @@ fire_dchrg(struct shpstr *sp, struct shpstr *targ, int ntargets)
 	return;
 
     /* ok, all set.. now, we shoot */
-    shells -= ldround(((double)gun) / 2.0, 1);
+    shells -= ldround(gun / 2.0, 1);
     sp->shp_item[I_SHELL] = shells;
     putship(sp->shp_uid, sp);
 
diff --git a/src/lib/common/move.c b/src/lib/common/move.c
index 83faddf8..34df9b95 100644
--- a/src/lib/common/move.c
+++ b/src/lib/common/move.c
@@ -51,9 +51,9 @@ sector_mcost(struct sctstr *sp, int do_bonus)
 /* Note, the best you can get is a 1.0 here. */
 
     if (do_bonus == MOB_ROAD) {
-	d = d / (1.0 + ((double)sp->sct_road / 122.0));
+	d = d / (1.0 + sp->sct_road / 122.0);
     } else if (do_bonus == MOB_RAIL) {
-	d = d / (1.0 + ((double)sp->sct_rail / 100.0));
+	d = d / (1.0 + sp->sct_rail / 100.0);
     } else {
 	if (d < 2.0)
 	    d = 2.0;
@@ -61,10 +61,10 @@ sector_mcost(struct sctstr *sp, int do_bonus)
     if (d < 1.0)
 	d = 1.0;
     if (dchr[sp->sct_type].d_mcst < 25)
-	d = (d * 100.0 - (double)sp->sct_effic) / 500.0;
-/*	d = (200.0 + (d - 3.0) * (double)sp->sct_effic) / 500.0;*/
+	d = (d * 100.0 - sp->sct_effic) / 500.0;
+/*	d = (200.0 + (d - 3.0) * sp->sct_effic) / 500.0;*/
     else
-	d = (d * 10.0 - (double)sp->sct_effic) / 115;
+	d = (d * 10.0 - sp->sct_effic) / 115;
 
     if (d <= 0.0 || d < MIN_MOBCOST)
 	return MIN_MOBCOST;
diff --git a/src/lib/common/path.c b/src/lib/common/path.c
index 7a3fcc05..aa335dbb 100644
--- a/src/lib/common/path.c
+++ b/src/lib/common/path.c
@@ -265,8 +265,8 @@ bp_realcost(struct as_coord from, struct as_coord to, void *pp)
 static double
 bp_seccost(struct as_coord from, struct as_coord to, void *pp)
 {
-    return (double)mapdist((coord)from.x, (coord)from.y,
-			   (coord)to.x, (coord)to.y);
+    return mapdist((coord)from.x, (coord)from.y,
+		   (coord)to.x, (coord)to.y);
 }
 
 /*
diff --git a/src/lib/gen/chance.c b/src/lib/gen/chance.c
index 61a59829..1898d011 100644
--- a/src/lib/gen/chance.c
+++ b/src/lib/gen/chance.c
@@ -40,7 +40,7 @@ chance(double d)
 {
     double roll;
 
-    roll = (random() & 0x7fff);
+    roll = random() & 0x7fff;
 
     if (d > roll / 32768.0)
 	return 1;
@@ -50,7 +50,7 @@ chance(double d)
 int
 roll(int n)
 {
-    return (random() % n) + 1;
+    return 1 + random() % n;
 }
 
 /*
diff --git a/src/lib/subs/landgun.c b/src/lib/subs/landgun.c
index 6f743e5b..ecf68df3 100644
--- a/src/lib/subs/landgun.c
+++ b/src/lib/subs/landgun.c
@@ -43,11 +43,10 @@ double
 landgun(int effic, int guns)
 {
     double d;
-    double g = (double)MIN(guns, 7);
+    double g = MIN(guns, 7);
 
-    d = ((double)(random() % 30) + 20.0) * ((double)g / 7.0);
-    d *= (double)effic;
-    d /= 100.0;
+    d = (random() % 30 + 20.0) * (g / 7.0);
+    d *= effic / 100.0;
     return d;
 }
 
@@ -58,8 +57,8 @@ seagun(int effic, int guns)
 
     d = 0.0;
     while (guns--)
-	d += 10.0 + (double)(random() % 6);
-    d *= (double)effic * 0.01;
+	d += 10.0 + random() % 6;
+    d *= effic * 0.01;
     return d;
 }
 
@@ -70,8 +69,8 @@ landunitgun(int effic, int shots, int guns, int ammo, int shells)
 
     shots = MIN(shots, guns);
     while (shots-- > 0)
-	d += 5.0 + (double)(random() % 6);
-    d *= (double)effic * 0.01;
+	d += 5.0 + random() % 6;
+    d *= effic * 0.01;
     if (shells < ammo && ammo != 0)
 	d *= (double)shells / (double)ammo;
     return d;
diff --git a/src/lib/subs/lndsub.c b/src/lib/subs/lndsub.c
index 4a911577..c89e9b66 100644
--- a/src/lib/subs/lndsub.c
+++ b/src/lib/subs/lndsub.c
@@ -176,8 +176,7 @@ lnd_take_casualty(int combat_mode, struct llist *llp, int cas)
 	eff_eq = 100;
 	llp->land.lnd_effic = 0;
     } else {
-	eff_eq =
-	    ldround((((double)cas * 100.0) / (double)llp->lcp->l_mil), 1);
+	eff_eq = ldround(cas * 100.0 / llp->lcp->l_mil, 1);
 	llp->land.lnd_effic -= eff_eq;
 	lnd_submil(&llp->land, cas);
     }
@@ -345,7 +344,7 @@ intelligence_report(int destination, struct lndstr *lp, int spy,
     memset(buf1, 0, sizeof(buf1));
     memset(buf2, 0, sizeof(buf2));
     memset(buf3, 0, sizeof(buf3));
-    if (chance((double)(spy + lp->lnd_vis) / 10.0)) {
+    if (chance((spy + lp->lnd_vis) / 10.0)) {
 	if (destination == player->cnum)
 	    pr("%s %s", mess, prland(lp));
 	else
@@ -353,8 +352,7 @@ intelligence_report(int destination, struct lndstr *lp, int spy,
 
 	estimate = lp->lnd_item[I_MILIT];
 
-	if (chance((double)(spy + lp->lnd_vis) / 20.0)) {
-
+	if (chance((spy + lp->lnd_vis) / 20.0)) {
 	    if (destination == player->cnum)
 		pr(" (eff %d, mil %d",
 		   roundintby(lp->lnd_effic, 5),
@@ -365,7 +363,7 @@ intelligence_report(int destination, struct lndstr *lp, int spy,
 			roundintby(lp->lnd_item[I_MILIT], 10));
 	    estimate = lp->lnd_item[I_MILIT] * lp->lnd_effic / 100.0;
 
-	    if (chance((double)(spy + lp->lnd_vis) / 20.0)) {
+	    if (chance((spy + lp->lnd_vis) / 20.0)) {
 		int t;
 		t = lp->lnd_tech - 20 + roll(40);
 		t = MAX(t, 0);
@@ -524,7 +522,7 @@ lnd_sel(struct nstr_item *ni, struct emp_qelem *list)
 	llp = malloc(sizeof(struct llist));
 	llp->lcp = lcp;
 	llp->land = land;
-	llp->mobil = (double)land.lnd_mobil;
+	llp->mobil = land.lnd_mobil;
 	emp_insque(&llp->queue, list);
     }
 }
@@ -593,7 +591,7 @@ lnd_mar(struct emp_qelem *list, double *minmobp, double *maxmobp,
 	if (land.lnd_x != allx || land.lnd_y != ally)
 	    *togetherp = 0;
 	if (land.lnd_mobil + 1 < (int)llp->mobil) {
-	    llp->mobil = (double)land.lnd_mobil;
+	    llp->mobil = land.lnd_mobil;
 	}
 	if (llp->mobil < *minmobp)
 	    *minmobp = llp->mobil;
@@ -821,7 +819,7 @@ lnd_damage(struct emp_qelem *list, int totdam)
 
     if (!totdam || !(count = lnd_count(list)))
 	return 0;
-    dam = ldround(((double)totdam / (double)count), 1);
+    dam = ldround((double)totdam / count, 1);
     for (qp = list->q_back; qp != list; qp = next) {
 	next = qp->q_back;
 	llp = (struct llist *)qp;
@@ -975,9 +973,9 @@ lnd_hardtarget(struct lndstr *lp)
     struct sctstr sect;
 
     getsect(lp->lnd_x, lp->lnd_y, &sect);
-    return (int)(((double)lp->lnd_effic / 100.0) *
-		 (10 + dchr[sect.sct_type].d_dstr * 2 +
-		  (double)lp->lnd_spd / 2.0 - lp->lnd_vis));
+    return (int)((lp->lnd_effic / 100.0) *
+		 (10 + dchr[sect.sct_type].d_dstr * 2 + lp->lnd_spd / 2.0
+		  - lp->lnd_vis));
 }
 
 static int
@@ -1019,7 +1017,7 @@ lnd_mobcost(struct lndstr *lp, struct sctstr *sp, int mobtype)
    bridge heads, bridges and highways have built-in highways bonus
    because they are a 1, and this will discount that. */
 
-    smobcost = (double)sector_mcost(sp, mobtype);
+    smobcost = sector_mcost(sp, mobtype);
     if (smobcost < 0.01)
 	smobcost = 0.01;
 
diff --git a/src/lib/subs/mission.c b/src/lib/subs/mission.c
index 74c568f6..f1391225 100644
--- a/src/lib/subs/mission.c
+++ b/src/lib/subs/mission.c
@@ -486,9 +486,8 @@ perform_mission(coord x, coord y, natid victim, struct emp_qelem *list,
 		dam2 = ldround(landunitgun(lp->lnd_effic, lp->lnd_dam, gun,
 					   lp->lnd_ammo, shell), 1);
 		if (sect.sct_type == SCT_WATER) {
-		    double dam3 = (double)dam2;
-		    if (chance(((double)lp->lnd_acc) / 100.0))
-			dam2 = ldround((dam3 / 2.0), 1);
+		    if (chance(lp->lnd_acc / 100.0))
+			dam2 = ldround(dam2 / 2.0, 1);
 		}
 		dam += dam2;
 		if (sect.sct_type == SCT_WATER)
@@ -527,7 +526,7 @@ perform_mission(coord x, coord y, natid victim, struct emp_qelem *list,
 		if (!(mcp->m_flags & M_DCH) && !(mcp->m_flags & M_SUBT))
 		    continue;
 		vrange = techfact(sp->shp_tech, mcp->m_vrnge);
-		vrange *= (double)sp->shp_effic / 200.0;
+		vrange *= sp->shp_effic / 200.0;
 		if (md > vrange)
 		    continue;
 		/* can't look all the time */
@@ -900,7 +899,7 @@ show_mission(int type, struct nstr_item *np)
 	    pr("  %4d", plus);
 	} else if (gp->mission == MI_ESCORT) {
 	    pr("        ");
-	    pr("  %4d", (int)(item.plane.pln_range / 2.0));
+	    pr("  %4d", item.plane.pln_range / 2);
 	} else
 	    pr("              ");
 	if (gp->mission)
@@ -1536,7 +1535,7 @@ air_defense(coord x, coord y, natid victim, struct emp_qelem *bomb_list,
 	for (qp = interceptors.q_forw; qp != (&interceptors);
 	     qp = qp->q_forw)
 	    tcount++;
-	tcount -= (count * 2);
+	tcount -= count * 2;
 	/* Just in case there are more incoming than we have */
 	if (tcount < 0)
 	    tcount = 0;
diff --git a/src/lib/subs/move.c b/src/lib/subs/move.c
index 5fdd967d..2f893a1a 100644
--- a/src/lib/subs/move.c
+++ b/src/lib/subs/move.c
@@ -63,7 +63,7 @@ move_ground(struct sctstr *start, struct sctstr *end,
     double sect_mcost;
     double total_mcost;
     double mv_cost;
-    double mobility = (double)start->sct_mobil;
+    double mobility = start->sct_mobil;
     int dir;
     int intcost;
     int takedam = *dam;
@@ -230,7 +230,7 @@ move_ground(struct sctstr *start, struct sctstr *end,
 	if (takedam && chance(weight / 100.0) &&
 	    ((curx != oldx) || (cury != oldy)))
 	    *dam += ground_interdict(curx, cury, player->cnum,
-				       "commodities");
+				     "commodities");
 	if (*dam >= 100)
 	    break;
     }
diff --git a/src/lib/subs/plnsub.c b/src/lib/subs/plnsub.c
index e1df6152..9229b6c0 100644
--- a/src/lib/subs/plnsub.c
+++ b/src/lib/subs/plnsub.c
@@ -1005,7 +1005,7 @@ plane_sweep(struct emp_qelem *plane_list, coord x, coord y)
 	if (!(pcp->pl_flags & P_SWEEP))	/* if it isn't an sweep plane */
 	    continue;
 
-	if (chance(((double)(100 - pp->pln_acc)) / 100.0)) {
+	if (chance((100.0 - pp->pln_acc) / 100.0)) {
 	    pr("Sweep! in %s\n",
 	       xyas(sect.sct_x, sect.sct_y, pp->pln_own));
 	    mines_there--;
diff --git a/src/lib/subs/satmap.c b/src/lib/subs/satmap.c
index 06bfde29..c9660042 100644
--- a/src/lib/subs/satmap.c
+++ b/src/lib/subs/satmap.c
@@ -208,7 +208,7 @@ satmap(int x, int y, int eff, int range, int flags, int type)
 	while (nxtitem(&ni, &land)) {
 	    if (land.lnd_own == 0)
 		continue;
-	    if (!chance((double)land.lnd_effic / 20.0))
+	    if (!chance(land.lnd_effic / 20.0))
 		continue;
 	    if (++crackle == 100)
 		crackle = 0;
@@ -326,7 +326,7 @@ satdisp(struct sctstr *sp, int acc, int showstuff)
     while (nxtitem(&ni, &land)) {
 	if (land.lnd_own == 0)
 	    continue;
-	if (!chance((double)land.lnd_effic / 20.0))
+	if (!chance(land.lnd_effic / 20.0))
 	    continue;
 
 	if (first) {
diff --git a/src/lib/subs/shpsub.c b/src/lib/subs/shpsub.c
index eb2a4ec6..bafa098a 100644
--- a/src/lib/subs/shpsub.c
+++ b/src/lib/subs/shpsub.c
@@ -107,7 +107,7 @@ shp_sel(struct nstr_item *ni, struct emp_qelem *list)
 	mlp = malloc(sizeof(struct mlist));
 	mlp->mcp = mcp;
 	mlp->ship = ship;
-	mlp->mobil = (double)ship.shp_mobil;
+	mlp->mobil = ship.shp_mobil;
 	emp_insque(&mlp->queue, list);
     }
 }
@@ -178,7 +178,7 @@ shp_nav(struct emp_qelem *list, double *minmobp, double *maxmobp,
 	if (ship.shp_x != allx || ship.shp_y != ally)
 	    *togetherp = 0;
 	if (ship.shp_mobil + 1 < (int)mlp->mobil) {
-	    mlp->mobil = (double)ship.shp_mobil;
+	    mlp->mobil = ship.shp_mobil;
 	}
 	if (mlp->mobil < *minmobp)
 	    *minmobp = mlp->mobil;
@@ -446,7 +446,7 @@ shp_damage(struct emp_qelem *list, int totdam, int wantflags,
     if (!totdam
 	|| !(count = shp_count(list, wantflags, nowantflags, x, y)))
 	return 0;
-    dam = ldround(((double)totdam / (double)count), 1);
+    dam = ldround((double)totdam / count, 1);
     for (qp = list->q_back; qp != list; qp = next) {
 	next = qp->q_back;
 	mlp = (struct mlist *)qp;
@@ -749,11 +749,11 @@ shp_hardtarget(struct shpstr *sp)
 
     vis = sp->shp_visib;
     getsect(sp->shp_x, sp->shp_y, &sect);
-    onsea = (sect.sct_type == SCT_WATER);
+    onsea = sect.sct_type == SCT_WATER;
     if (mcp->m_flags & M_SUB)
 	vis *= 4;
-    return (int)(((double)sp->shp_effic / 100.0) *
-		 (20 + (double)sp->shp_speed * onsea / 2.0 - vis));
+    return (int)((sp->shp_effic / 100.0) *
+		 (20 + sp->shp_speed * onsea / 2.0 - vis));
 }
 
 static int
@@ -955,9 +955,8 @@ shp_missile_defense(coord dx, coord dy, natid bombown, int hardtarget)
 
 	/* now calculate the odds */
 	gun = MIN(ship.shp_item[I_GUN], ship.shp_glim);
-	eff = (double)ship.shp_effic / 100.0;
-	teff =
-	    (((double)ship.shp_tech) / (((double)ship.shp_tech) + 200.0));
+	eff = ship.shp_effic / 100.0;
+	teff = ship.shp_tech / (ship.shp_tech + 200.0);
 	/* raise 4.5 for better interception -KHS */
 	hitchance = (int)(gun * eff * teff * 4.5) - hardtarget;
 	if (hitchance < 0)
@@ -1032,7 +1031,7 @@ shp_missdef(struct shpstr *sp, natid victim)
     mlp = malloc(sizeof(struct mlist));
     mlp->mcp = &mchr[(int)sp->shp_type];
     mlp->ship = *sp;
-    mlp->mobil = (double)sp->shp_mobil;
+    mlp->mobil = sp->shp_mobil;
     emp_insque(&mlp->queue, &list);
     sprintf(buf, "%s", prship(&mlp->ship));
 
diff --git a/src/lib/subs/supply.c b/src/lib/subs/supply.c
index f1fce1e2..6d417f36 100644
--- a/src/lib/subs/supply.c
+++ b/src/lib/subs/supply.c
@@ -111,8 +111,8 @@ resupply_commod(struct lndstr *lp, i_type type)
     }
 
     if (opt_FUEL && type == I_PETROL) {
-	int fuel_needed = (lp->lnd_fuelu * (((float)etu_per_update
-					     * land_mob_scale)) / 10.0);
+	int fuel_needed = lp->lnd_fuelu
+	    * ((float)etu_per_update * land_mob_scale) / 10.0;
 
 	while ((lp->lnd_fuel < fuel_needed) && lp->lnd_item[I_PETROL]) {
 	    lp->lnd_fuel += 10;
@@ -216,10 +216,10 @@ s_commod(int own, int x, int y, i_type type, int total_wanted,
 	packing = ip->i_pkg[dp->d_pkg];
 	if (packing > 1 && sect.sct_effic < 60)
 	    packing = 1;
-	weight = ((double)ip->i_lbs / (double)packing);
+	weight = (double)ip->i_lbs / packing;
 	mobcost = move_cost * weight;
 	if (mobcost > 0)
-	    can_move = ((double)sect.sct_mobil / mobcost);
+	    can_move = (double)sect.sct_mobil / mobcost;
 	else
 	    can_move = sect.sct_item[type] - minimum;
 	if (can_move > sect.sct_item[type] - minimum)
@@ -290,10 +290,10 @@ s_commod(int own, int x, int y, i_type type, int total_wanted,
 	packing = ip->i_pkg[dp->d_pkg];
 	if (packing > 1 && sect.sct_effic < 60)
 	    packing = 1;
-	weight = ((double)ip->i_lbs / (double)packing);
+	weight = (double)ip->i_lbs / packing;
 	mobcost = move_cost * weight;
 	if (mobcost > 0)
-	    can_move = ((double)sect.sct_mobil / mobcost);
+	    can_move = (double)sect.sct_mobil / mobcost;
 	else
 	    can_move = ship.shp_item[type] - minimum;
 	if (can_move > ship.shp_item[type] - minimum)
@@ -381,10 +381,10 @@ s_commod(int own, int x, int y, i_type type, int total_wanted,
 
 	min = get_minimum(&land, type);
 	ip = &ichr[type];
-	weight = ((double)ip->i_lbs);
+	weight = ip->i_lbs;
 	mobcost = move_cost * weight;
 	if (mobcost > 0)
-	    can_move = ((double)land.lnd_mobil / mobcost);
+	    can_move = (double)land.lnd_mobil / mobcost;
 	else
 	    can_move = land.lnd_item[type] - min;
 	if (can_move > land.lnd_item[type] - min)
@@ -438,8 +438,7 @@ get_minimum(struct lndstr *lp, i_type type)
     case I_FOOD:
 	if (opt_NOFOOD)
 	    return 0;		/* no food reqd, get out */
-	want = (((double)etu_per_update * eatrate) *
-		(double)lp->lnd_item[I_MILIT]) + 1;
+	want = (double)etu_per_update * eatrate * lp->lnd_item[I_MILIT] + 1;
 	break;
     case I_SHELL:
 	want = lp->lnd_ammo;
@@ -448,18 +447,15 @@ get_minimum(struct lndstr *lp, i_type type)
 	/*
 	 * return the amount of pet we'd need to get to 
 	 * enough fuel for 1 update
-	 *
 	 */
     case I_PETROL:
 	if (opt_FUEL == 0)
 	    return 0;
-	want = (lp->lnd_fuelu * (((float)etu_per_update *
-				  land_mob_scale)) / 10.0);
+	want = lp->lnd_fuelu * ((float)etu_per_update * land_mob_scale)
+	    / 10.0;
 	want -= lp->lnd_fuel;
 	if (want > 0) {
-	    double d;
-	    d = (double)want / 10.0;
-	    want = (int)d;
+	    want = want / 10;
 	    if (want == 0)
 		want++;
 	}
@@ -518,7 +514,7 @@ has_supply(struct lndstr *lp)
 	fuel = lp->lnd_fuel;
 	if (fuel < fuel_needed) {
 	    petrol_needed =
-		ldround(((double)(fuel_needed - fuel) / 10.0), 1);
+		ldround((fuel_needed - fuel) / 10.0, 1);
 	    petrol = keeppetrol = lp->lnd_item[I_PETROL];
 	    if (petrol < petrol_needed) {
 		lp->lnd_item[I_PETROL] = 0;
@@ -582,7 +578,7 @@ use_supply(struct lndstr *lp)
 
 	if (fuel < fuel_needed) {
 	    petrol_needed =
-		ldround(((double)(fuel_needed - fuel) / 10.0), 1);
+		ldround((fuel_needed - fuel) / 10.0, 1);
 	    petrol = lp->lnd_item[I_PETROL];
 	}
 
diff --git a/src/lib/update/human.c b/src/lib/update/human.c
index 27a6c21f..0efa96f5 100644
--- a/src/lib/update/human.c
+++ b/src/lib/update/human.c
@@ -99,7 +99,7 @@ do_feed(struct sctstr *sp, struct natstr *np, short *vec,
 		   supply ships in port, or supply units */
 		int needed;
 
-		needed = ldround((double)(1 + etu * people * eatrate), 1);
+		needed = ldround(1.0 + etu * people * eatrate, 1);
 
 		/* Now, find some food */
 		vec[I_FOOD] = supply_commod(sp->sct_own,
diff --git a/src/lib/update/mobility.c b/src/lib/update/mobility.c
index cce9bb91..fbacfd9f 100644
--- a/src/lib/update/mobility.c
+++ b/src/lib/update/mobility.c
@@ -306,26 +306,26 @@ do_mob_ship(struct shpstr *sp, int etus)
 
     /* opt_FUEL in force */
     if (mchr[(int)sp->shp_type].m_fuelu == 0) {
-	value = sp->shp_mobil + ((float)etus * ship_mob_scale);
+	value = sp->shp_mobil + (float)etus * ship_mob_scale;
 	if (value > ship_mob_max)
 	    value = ship_mob_max;
 	sp->shp_mobil = (signed char)value;
     } else {
 	can_add = ship_mob_max - sp->shp_mobil;
-	if (can_add > ((float)etus * ship_mob_scale))
-	    can_add = ((float)etus * ship_mob_scale);
-	have_fuel_for = ldround((((double)sp->shp_fuel /
-				  (double)mchr[(int)sp->shp_type].m_fuelu)
-				 * (double)fuel_mult), 1);
+	if (can_add > (float)etus * ship_mob_scale)
+	    can_add = (float)etus * ship_mob_scale;
+	have_fuel_for = ldround(((double)sp->shp_fuel /
+				 (double)mchr[(int)sp->shp_type].m_fuelu)
+				* (double)fuel_mult, 1);
 
 	if (can_add > have_fuel_for) {
 	    int need;
 	    need = can_add - have_fuel_for;
-	    d = (double)need;
-	    d *= (double)mchr[(int)sp->shp_type].m_fuelu;
-	    d /= (double)fuel_mult;
+	    d = need;
+	    d *= mchr[(int)sp->shp_type].m_fuelu;
+	    d /= fuel_mult;
 	    d /= 5.0;
-	    if ((d - (int)d) > 0.0)
+	    if (d - (int)d > 0.0)
 		d++;
 	    need = (int)d;
 	    newfuel = supply_commod(sp->shp_own, sp->shp_x, sp->shp_y,
@@ -333,18 +333,18 @@ do_mob_ship(struct shpstr *sp, int etus)
 	    sp->shp_fuel += newfuel * 5;
 	}
 
-	have_fuel_for = ldround((((double)sp->shp_fuel /
-				  (double)mchr[(int)sp->shp_type].m_fuelu)
-				 * (double)fuel_mult), 1);
+	have_fuel_for = ldround(((double)sp->shp_fuel /
+				 (double)mchr[(int)sp->shp_type].m_fuelu)
+				* (double)fuel_mult, 1);
 
 	if (can_add > have_fuel_for) {
 	    int need;
 	    need = can_add - have_fuel_for;
-	    d = (double)need;
-	    d *= (double)mchr[(int)sp->shp_type].m_fuelu;
-	    d /= (double)fuel_mult;
+	    d = need;
+	    d *= mchr[(int)sp->shp_type].m_fuelu;
+	    d /= fuel_mult;
 	    d /= 50.0;
-	    if ((d - (int)d) > 0.0)
+	    if (d - (int)d > 0.0)
 		d++;
 	    need = (int)d;
 	    newfuel = supply_commod(sp->shp_own, sp->shp_x, sp->shp_y,
@@ -352,17 +352,17 @@ do_mob_ship(struct shpstr *sp, int etus)
 	    sp->shp_fuel += newfuel * 50;
 	}
 
-	have_fuel_for = ldround((((double)sp->shp_fuel /
-				  (double)mchr[(int)sp->shp_type].m_fuelu)
-				 * (double)fuel_mult), 1);
+	have_fuel_for = ldround(((double)sp->shp_fuel /
+				 (double)mchr[(int)sp->shp_type].m_fuelu)
+				* (double)fuel_mult, 1);
 
 	if (can_add > have_fuel_for)
 	    total_add = have_fuel_for;
 	else
 	    total_add = can_add;
-	d = (double)total_add;
-	d *= (double)mchr[(int)sp->shp_type].m_fuelu;
-	d /= (double)fuel_mult;
+	d = total_add;
+	d *= mchr[(int)sp->shp_type].m_fuelu;
+	d /= fuel_mult;
 	sp->shp_fuel -= ldround(d, 1);
 	sp->shp_fuel = MIN(sp->shp_fuel, mchr[(int)sp->shp_type].m_fuelc);
 	sp->shp_mobil += total_add;
@@ -429,19 +429,19 @@ do_mob_land(struct lndstr *lp, int etus)
 
 	can_add = land_mob_max - lp->lnd_mobil;
 
-	if (can_add > ((float)etus * land_mob_scale))
-	    can_add = ((float)etus * land_mob_scale);
+	if (can_add > (float)etus * land_mob_scale)
+	    can_add = (float)etus * land_mob_scale;
 
 	have_fuel_for = (lp->lnd_fuel / lp->lnd_fuelu) * fuel_mult;
 
 	if (can_add > have_fuel_for) {
 	    int need;
 	    need = can_add - have_fuel_for;
-	    d = (double)need;
-	    d *= (double)lp->lnd_fuelu;
-	    d /= (double)fuel_mult;
+	    d = need;
+	    d *= lp->lnd_fuelu;
+	    d /= fuel_mult;
 	    d /= 5.0;
-	    if ((d - (int)d) > 0.0)
+	    if (d - (int)d > 0.0)
 		d++;
 	    need = (int)d;
 	    newfuel = supply_commod(lp->lnd_own, lp->lnd_x, lp->lnd_y,
@@ -454,11 +454,11 @@ do_mob_land(struct lndstr *lp, int etus)
 	if (can_add > have_fuel_for) {
 	    int need;
 	    need = can_add - have_fuel_for;
-	    d = (double)need;
-	    d *= (double)lp->lnd_fuelu;
-	    d /= (double)fuel_mult;
+	    d = need;
+	    d *= lp->lnd_fuelu;
+	    d /= fuel_mult;
 	    d /= 50.0;
-	    if ((d - (int)d) > 0.0)
+	    if (d - (int)d > 0.0)
 		d++;
 	    need = (int)d;
 	    newfuel = supply_commod(lp->lnd_own, lp->lnd_x, lp->lnd_y,
@@ -472,9 +472,9 @@ do_mob_land(struct lndstr *lp, int etus)
 	    total_add = have_fuel_for;
 	} else
 	    total_add = can_add;
-	d = (double)total_add;
-	d *= (double)lp->lnd_fuelu;
-	d /= (double)fuel_mult;
+	d = total_add;
+	d *= lp->lnd_fuelu;
+	d /= fuel_mult;
 	lp->lnd_fuel -= ldround(d, 1);
 	lp->lnd_fuel = MIN(lp->lnd_fuel, lp->lnd_fuelc);
 	lp->lnd_mobil += total_add;
diff --git a/src/lib/update/nav_ship.c b/src/lib/update/nav_ship.c
index 9c8e5018..13e6ff9d 100644
--- a/src/lib/update/nav_ship.c
+++ b/src/lib/update/nav_ship.c
@@ -262,7 +262,7 @@ nav_ship(struct shpstr *sp)
     mlp = malloc(sizeof(struct mlist));
     mlp->mcp = mchr + sp->shp_type;
     mlp->ship = *sp;
-    mlp->mobil = (double)sp->shp_mobil;
+    mlp->mobil = sp->shp_mobil;
     emp_insque(&mlp->queue, &ship_list);
 
     quit = 1;			/* setup loop, we want to check it 1 time. */
diff --git a/src/lib/update/nav_util.c b/src/lib/update/nav_util.c
index 8c3933ff..3171e83a 100644
--- a/src/lib/update/nav_util.c
+++ b/src/lib/update/nav_util.c
@@ -212,10 +212,10 @@ auto_fuel_ship(struct shpstr *sp)
     if (opt_FUEL == 0)
 	return;
     getship(sp->shp_uid, sp);	/* refresh */
-    /* fill with petro */
+    /* fill with petrol */
     maxfuel = mchr[(int)sp->shp_type].m_fuelc;
-    d = (double)maxfuel / 5.0;
-    if ((d - (int)d > 0.0))
+    d = maxfuel / 5.0;
+    if (d - (int)d > 0.0)
 	d++;
     need = (int)d;
 
@@ -233,8 +233,8 @@ auto_fuel_ship(struct shpstr *sp)
     }
     add_fuel = 0;
     /* fill with oil */
-    d = (double)(maxfuel - totalfuel) / 50.0;
-    if ((d - (int)d > 0.0))
+    d = (maxfuel - totalfuel) / 50.0;
+    if (d - (int)d > 0.0)
 	d++;
     need = (int)d;
 
diff --git a/src/lib/update/plague.c b/src/lib/update/plague.c
index 1915a553..f117588a 100644
--- a/src/lib/update/plague.c
+++ b/src/lib/update/plague.c
@@ -170,7 +170,7 @@ plague_people(struct natstr *np, short *vec,
 	plg_num = 100.0 * etus;
 	plg_denom = (np->nat_level[NAT_RLEV] + 100.0) *
 	    (*ptime + etus + 1.0);
-	pct_left = 1.0 - (double)(plg_num / plg_denom);
+	pct_left = 1.0 - plg_num / plg_denom;
 	if (pct_left < 0.2)
 	    pct_left = 0.2;
 	vec[I_CIVIL] = vec[I_CIVIL] * pct_left;
diff --git a/src/lib/update/populace.c b/src/lib/update/populace.c
index 2bb5349a..1058a929 100644
--- a/src/lib/update/populace.c
+++ b/src/lib/update/populace.c
@@ -95,7 +95,7 @@ populace(struct natstr *np, struct sctstr *sp, int etu)
 	if (n < 0)
 	    n = 0;
 	sp->sct_work = n;
-	if (chance((double)work_red / 1000.0)) {
+	if (chance(work_red / 1000.0)) {
 	    /*
 	     * small chance of rebellion...
 	     * if work_red is (max) 67,
diff --git a/src/lib/update/sect.c b/src/lib/update/sect.c
index 887f1811..e2dd1cff 100644
--- a/src/lib/update/sect.c
+++ b/src/lib/update/sect.c
@@ -258,7 +258,7 @@ decay_fallout(struct sctstr *sp, int etus)
 
     if (etus > 24)
 	etus = 24;
-    decay = roundavg(((decay_per_etu + 6.0) * fallout_spread) *
+    decay = roundavg((decay_per_etu + 6.0) * fallout_spread *
 		     (double)etus * (double)sp->sct_fallout);
 
     sp->sct_fallout = decay < sp->sct_fallout ? sp->sct_fallout - decay : 0;
diff --git a/src/lib/update/ship.c b/src/lib/update/ship.c
index 07e2dce4..51c8ffa1 100644
--- a/src/lib/update/ship.c
+++ b/src/lib/update/ship.c
@@ -171,8 +171,8 @@ upd_ship(struct shpstr *sp, int etus,
 					         sp->shp_item[I_MILIT],
 						 sp->shp_item[I_UW],
 						 ITEM_MAX)
-				      * (double)sp->shp_effic / 100.0
-				      * (double)sectp->sct_oil / 100.0
+				      * sp->shp_effic / 100.0
+				      * sectp->sct_oil / 100.0
 				      * prod_eff(product, sp->shp_tech));
 		max_oil = mp->m_item[I_OIL];
 		if (sp->shp_item[I_OIL] + oil_gained > max_oil)
diff --git a/src/server/shutdown.c b/src/server/shutdown.c
index 081dc281..a40200d3 100644
--- a/src/server/shutdown.c
+++ b/src/server/shutdown.c
@@ -87,7 +87,7 @@ shutdown_sequence(void *unused)
 			header, shutdown_pending);
 	    } else if (shutdown_pending % 60 == 0) {
 		pr_wall("%sThe server will be shutting down %d hours from now.\n",
-			header, (int)(shutdown_pending / 60));
+			header, shutdown_pending / 60);
 	    }
 	}
 	empth_sleep(now + 60);