Why do my shots bounce even when penetration value is higher than armor?

Because the impact angle multiplies armor (up to a 70° auto-bounce). Aim at plates as flat as possible, or hit caliber-overmatched thin sections.

What is the 2x overmatch rule?

If your shell’s caliber is at least twice the nominal armor thickness, AP/APCR shells do not auto-bounce even at extreme angles — penetration is still rolled, but not denied outright.

APCR or HEAT premium ammo?

APCR generally: it keeps normalization, flies faster and handles spaced armor and angles. HEAT only when facing flat, very thick single plates.

How do I penetrate a Maus or E 100 frontally?

Angle defeats them: force them to expose sides by flanking, shoot lower plates and turret rings with standard ammo, and use HE to break their periscopes when nothing else works.

Does RNG decide penetration?

Penetration rolls ±25% around the displayed value, but geometry decides far more: a well-angled 150 mm plate shrugs off shells rated for 250 mm at flat impact.

Armor and Penetration Mechanics Explained (WoT)

Effective armor: the angle multiplies everything

A plate’s real resistance is its nominal thickness divided by the cosine of the impact angle (measured from the shell’s path to the plate’s perpendicular). In practice:

Hit at 0° (flat): 100 mm plate = 100 mm effective.
Hit at 30°: ~115 mm effective.
Hit at 60°: ~200 mm effective — twice the nominal value.

This is why sidescraping works: angling your hull 30–45° toward the enemy multiplies your side armor while keeping your front relevant. It is also why shooting a slightly turned turret cheek or an angled lower plate fails — the geometry, not the thickness, defeated you.

Shell normalization and ricochet rules

AP and APCR normalize by 5° — the game treats the impact as 5° more favorable than reality, rewarding careful aiming.
Ricochet (auto-bounce): AP/APCR shells hitting at more than 70° from the plate’s normal will bounce — unless the shell caliber is at least twice the armor thickness (the “2× overmatch” rule), in which case penetration is calculated instead of an automatic bounce. That is why big guns ignore the flimsy sides light tanks angle.
HEAT has no normalization and loses penetration quickly against spaced armor and tracks, but it does not auto-bounce at 70° — it struggles below ~85°. Against flat, thick armor, premium HEAT usually wins; against angles and spaced plates, APCR usually wins.
HE and HESH penetrate with no normalization and low values; their damage falls off against armor. Use them for finishing low-HP targets, resetting caps and breaking modules.

Reading weak spots like a checklist

Every tank has a pattern; learn the pattern, not the pixel:

Lower plate — thinner than the upper front plate on most tanks; aim below the headlights.
Cupolas and hatches — the small bumps on turret roofs; high risk/high reward at range.
Turret ring and overtrack shots — where hull meets turret, and shooting above the tracks into the hull side.
Sides and rear — if you are flanking (you should be — see the medium tank guide), sides are almost always green.
Roofs and engine decks — artillery and high-explosive loves thin top armor; sometimes your AP does too on overmatched engine decks.

When premium (gold) ammo is actually correct

Breaking a stalled engagement — the corner you must clear to win the flank.
Super-heavies your standard pen cannot crack frontally — or better, reposition instead (a bounced 4,000-credit shell is a double loss).
Endgame executes — the last 200 HP of a winning trade.

Gold ammo is a tactical tool, not a loadout. Economically, standard ammo with aimed weak spots earns far more (credit guide).

Trading efficiently with mechanics

Angle before you peek, not during. Pre-angled sidescrapes bounce for free.
Shoot on the enemy’s reload rhythm — count the shots of autoloaders and punish the drum.
Use double-bushes and ridge lines so your trades are asymmetric: you shoot, they cannot see you (spotting guide).
Track + damage beats pure damage early: a tracked enemy is exposed to your whole team.

Put together, these mechanics are why two tanks with identical stats produce wildly different results — armor geometry is a skill multiplier you control every second of the battle.