Essen had been instructed to divide his forces and attack Ostralenka from both banks of the River Narew. For the scenario, the Russian commander had to allocate his divisions to either the right or left bank attack before seeing the French deployment. In addition to reflect the difficulty of co-ordinating an attack separated by a river he had to dice to see which force arrived first and also for the delay before the second force arrived.
The French have sufficient troops to hold Ostralenka and its defences against an attack from the east (left bank). However, a cavalry patrol has captured a copy of Essen's orders and Savary, the French commander, is aware of the attack along the right bank. He therefore has to deploy half his force to meet this threat. Reinforcements in the shape of Gudin's division are on their way, but their arrival will be determined by die roll (20 on a d20, then 19 or 20, 18-20, etc on successive turns, starting on turn 3).
Essen decided to make his main attack on the left bank, using 2 line infantry divisions (generals Somov and Lieven) with 12 battalions, plus Tutschkov's Grenadier Brigade (4 battalions), the bulk of the artillery, 3 foot batteries and one heavy battery, was also allocated to this attack. This left Korf's cavalry division (two light and 2 dragoon regiments) plus Samsonov's Advance Guard division of 4 jaeger battalions, two skirmisher stands, two units of cossacks and horse battery, to occupy Morand's attention. Essen's dice roll resulted in the right bank attack arriving first with the main attack delayed by two turns.
On turn one Samsonov's troops marched onto the table and made straight for the line of French infantry defending the stream. Korf's cavalry moved to the right of their infantry hoping to outflank the French position. Morand's skirmishers pulled back to the main line as the cavalry advanced and the two battalions of the 8th Legere which Morand had posted on the ridge, formed square as the Alexandrinsk Hussars came closer. With the French infantry pinned, Korf continued to move to his right to outflank the French position. As his men rounded the low ridge they were surprised to find D'Hautpol's cavalry opposing them. A typically confused cavalry melee took place with both sides falling back to reform having inflicted very little damage. Meanwhile the Russian jaegers had been struggling to make progress against Morand's infantry which had a foot battery to support them. Initially, the Frenchmen had support from Leval's troops on the left bank of the Narew, but these moved away once Essen's main attack force made it's presence felt. The Russian 8th jaeger attempted to charge across the stream against the 46th Ligne, but were stopped in their tracks by a crushing volley. The jaeger's right flank was threatened by the 8th Legere but a combination of Cossacks, skirmishers and the horse battery occupied their attention and for a time the Russian position held.
Savary's main concern was the mass of Russian infantry bearing down on Ostralenka on the left bank. Essen had ordered the three columns to encircle the French defences, stretching the defenders' resources. Lieven's column did suffer from the attention of the French foot artillery, but it persevered and finally reached the Narew where it turned to face the town. On Essen's opposite flank Tutschkov's grenadiers had no such problem, only a single battalion (the 2nd) of the 10th Ligne held the defences opposite them. Two battalions attacked frontally, two moved around the flank. After a brief struggle, the 2nd battalion broke and the survivors ran for the bridge. In the centre Somov's attack had not been so impressive. The artillery had proved ineffective at long range and the Russian attack dissolved into a bloody shambles. Two battalions battered themselves to destruction against the French in successive attacks. Two more attacks came to naught in the face of defensive volleys. It was only the intervention of the 2nd battalion of the Moscow Grenadier regiment which saved Somov's command. Swinging to their right after driving off the 2nd battalion of the 20th Ligne, the battalion attacked the flank of the 4th battalion of the 10th and crushed it. Seeing this the previously Leval's previously invincible men broke and ran for the bridge. (Actually they had an unlucky die roll on the divisional morale test for one third losses). Secure on the right bank of the Narew Leval attempted with little success to rally his men and lead them back into action. This could have handed the game to the Russians, but on turn 4, on a 10% chance Gudins's division had arrived. Savary had moved them towards Ostralenka and with fixed bayonets the men of the 23rd Ligne forced their way through Leval's troops to continue the defence of the left bank.
Meanwhile Morand and D'Hautpol had continued their fight with the Russian right bank attack. The 7th Dragoons covered themselves with glory driving the Russian Uhlans from the field and then forcing the New Russland Dragoons to withdraw. The 23rd Dragoons caught the Riga Dragoons as they tried to reform following a clash with the 7th Dragoons and drove them from the field too. The sole remaining Russian cavalry (apart from the Cossacks) were the Alexandrinsk Hussars. Morand had ordered the two battalions of the 8th Legere to form line as the bulk of the Russian cavalry was destroyed. Seeing this, Korf ordered the Hussars to move forward to force the French back into square, otherwise Samsonov's remaining jaegers would be attacked in flank. Realising the importance of maintaining his unit as a fighting force, the colonel ordered a feint attack against the Frenchmen. As the horsemen advanced the veteran French infantry quickly formed square and job done the colonel ordered the trumpeter to sound the halt. Unfortunately, the trumpeter's calls were not heard above the sounds of battle and the charge continued (ie the Russians failed the morale test) . The result of the melee was never really in doubt, full strength light cavalry units would require a 6 - 1 result in their favour to succeed. The Alexandrinsk had sustained some casualties from fire and therefore carried a -1 into the melee. The dice were not kind and the hussars were destroyed. Samsonov had by now only two jaeger battalions left and one of those faced three opponents. In a brief fire fight it offered brave but futile resistance before being destroyed. However, Samsonov could draw some comfort from the sight of one of the French battlions being destroyed by canister from the horse battery and the French foot battery losing its final gunners to a volley from the 2nd battalion of the 26th jaeger. But with no cavalry support and only a shadow of his command with the colours Samsonov felt he could do no more and began to fall back. For his part Morand had orders to defend the ridge and with no further instructions coming from Savary he held his ground and tended to the wounded.
Gudin was fighting hard on the left bank. His lead battalions had just taken up position in the town sectors when the first Russian attacks rolled in. The grenadiers attacking his right suffered from the fire of his artillery and the first attack achieved nothing. On his left Lieven's men were taking horrific casualties from the foot battery left behind by Leval and could make no impression on the defences of the town. Indeed, after a third unsuccessful attack Lieven's men, like Leval's before them failed a divisional morale test and had to retreat and attempt to rally. In a final throw Essen ordered in the battered remnants of Somov's division and they succeeded where Lieven had failed, driving out the tenacious French defenders. By the bridge Tutschkov's grenadiers eventually drove out their opponents so the left bank part of Ostralenka had been secured.
Gudin attempted to recover a foothold on the left bank, but his attacks failed and as night fell both sides took what shelter they could. The result was a draw. The Russians could claim that they had driven the French back across the river; the French that they had denied the Russians a foothold on the right bank.